MyMedR

Displaying publications 1001 - 1020 of 4089 in total

Abstract:

Sort:

Effects of dietary protein level on growth and ammonia excretion of leopard coral grouper, plectropomus leopardus (lacepede, 1802)

Feng S, S. Xia ZS, Zhang Z, Rahman M, Rajkumar M

Sains Malaysiana, 2015;44:537-543.

The effects of dietary protein level on the growth performance and ammonia excretion of the leopard coral grouper,
Plectropomus leopardus were investigated for eight weeks. Fish were fed diets with 40, 45, 50, 55 and 60% crude protein
levels in separate recirculating systems. Fish fed with the 50% crude protein containing diet showed the best ingestion
rate, which was significantly higher than that found in the other groups. As the dietary protein level increased, the
specific growth rate increased significantly and it reached the highest level at 50% crude protein containing diet. Based
on the results of all measured parameters 50% protein containing diet was the best among all test diets. The regression
equation for dietary protein level versus ammonia excretion indicated that the optimal dietary protein level with the
least ammonia excretion was 53.14%. More research is still needed to elucidate the effects of 53.14% crude protein
containing diet on the specific growth rate, feed conversion ratio, protein efficiency ratio and ingestion rate of leopard
coral grouper before recommending this level. Until then, 50% protein containing diet can be recommended for leopard
coral grouper culture in the recirculation system.

Matched MeSH terms: Dietary Proteins
Transformasi gen metalotionin (eiMT1) daripada eleusine indica ke dalam pokok tembakau, nicotiana tabacum berperantaraan agrobacterium tumefaciens

Nik Marzuki Sidik, Roslina Mat Yazid, Che Radziah Che Mohd. Zain, Ismanizan Ismail

Sains Malaysiana, 2010;39.

Metalotionin (MT ) merupakan protein pengikat logam berberat molekul rendah dan kaya dengan sistein yang hadir dalam pelbagai jenis organisma termasuklah bakteria, kulat, tumbuhan dan haiwan. MT tumbuhan dipercayai mengambil bahagian dalam metabolisme dan penyahtoksikan logam dengan cara pengkelatan ion-ion logam berat. Fungsinya yang unik ini telah mendorong minat untuk memencilkan gen MT daripada rumput sambau, Eleusine indica. DNA pelengkap (cDNA) eiMT 1 telah diklonkan ke dalam vektor binari pBI121 untuk ditransformasikan ke dalam pokok tembakau melalui perantaraan Agrobacterium tumefaciens. Penyaringan pokok tembakau transgenik dengan PCR dilakukan menggunakan 3 pasang pencetus yang direka khas iaitu pasangan CMT F dan CMT R, 35SF dan PMT R, dan pasangan pencetus khusus-gen MT FS2 dan MT RS2. Ketiga-tiga pasangan pencetus ini berjaya menghasilkan saiz serpihan DNA jangkaan iaitu masing-masing 270 pb, 1.1 kb dan 170 pb. Penjujukan terhadap serpihan bersaiz 170 pb dan analisis jujukan menunjukkan persamaan 100 % dengan eiMT 1. Kajian pengekspresan gen melalui pendekatan transkripsi berbalik-PCR membuktikan bahawa transgen eiMT 1 telah berjaya diekspreskan dalam 11 daripada 19 pokok transgenik yang dikaji.

Matched MeSH terms: Proteins
Erythrocyte membrane deformability and stability: two distinct membrane properties that are independently regulated by skeletal protein associations

Chasis JA, Mohandas N

J. Cell Biol., 1986 Aug;103(2):343-50.
PMID: 3733870

Skeletal proteins play an important role in determining erythrocyte membrane biophysical properties. To study whether membrane deformability and stability are regulated by the same or different skeletal protein interactions, we measured these two properties, by means of ektacytometry, in biochemically perturbed normal membranes and in membranes from individuals with known erythrocyte abnormalities. Treatment with 2,3-diphosphoglycerate resulted in membranes with decreased deformability and decreased stability, whereas treatment with diamide produced decreased deformability but increased stability. N-ethylmaleimide induced time-dependent changes in membrane stability. Over the first minute, the stability increased; but with continued incubation, the membranes became less stable than control. Meanwhile, the deformability of these membranes decreased with no time dependence. Biophysical measurements were also carried out on pathologic erythrocytes. Membranes from an individual with hereditary spherocytosis and a defined abnormality in spectrin-protein 4.1 association showed decreased stability but normal deformability. In a family with hereditary elliptocytosis and an abnormality in spectrin self-association, the membranes had decreased deformability and stability. Finally, membranes from several individuals with Malaysian ovalocytosis had decreased deformability but increased stability. Our data from both pathologic membranes and biochemically perturbed membranes show that deformability and stability change with no fixed relationship to one another. These findings imply that different skeletal protein interactions regulate membrane deformability and stability. In light of these data, we propose a model of the role of skeletal protein interactions in deformability and stability.

Matched MeSH terms: Cytoskeletal Proteins/blood*; Membrane Proteins/blood*
Fulltext The major allergen Der p 2 is a cholesterol binding protein

Reginald K, Chew FT

Sci Rep, 2019 02 07;9(1):1556.
PMID: 30733527 DOI: 10.1038/s41598-018-38313-9

Der p 2 is a major dust mite allergen and >80% of mite allergic individuals have specific IgE to this allergen. Although it is well characterized in terms of allergenicity, there is still some ambiguity in terms of its biological function. Three-dimensional structural analysis of Der p 2 and its close homologues indicate the presence of a hydrophobic cavity which can potentially bind to lipid molecules. In this study, we aimed to identify the potential ligand of Der p 2. Using a liposome pulldown assay, we show that recombinant Der p 2 binds to liposomes prepared with exogenous cholesterol in a dose dependent fashion. Next, an ELISA based assay using immobilized lipids was used to study binding specificities of other lipid molecules. Cholesterol was the preferred ligand of Der p 2 among 11 different lipids tested. Two homologues of Der p 2, Der f 2 and Der f 22 also bound to cholesterol. Further, using liquid chromatography-mass spectrometry (LC-MS), we confirmed that cholesterol is the natural ligand of Der p 2. Three amino acid residues of Der p 2, V104, V106 and V110 are possible cholesterol binding sites, as alanine mutations of these residues showed a significant decrease in binding (p

Matched MeSH terms: Arthropod Proteins/genetics; Arthropod Proteins/metabolism*; Arthropod Proteins/chemistry
Protease activity is maintained in Nepenthes ampullaria digestive fluids depleted of endogenous proteins with compositional changes

Ravee R, Baharin A, Cho WT, Ting TY, Goh HH

Physiol Plant, 2021 Dec;173(4):1967-1978.
PMID: 34455610 DOI: 10.1111/ppl.13540

Nepenthes ampullaria is a unique carnivorous tropical pitcher plant with the detritivorous capability of sequestering nutrients from leaf litter apart from being insectivorous. The changes in the protein composition and protease activity of its pitcher fluids during the early opening of pitchers (D0 and D3C) were investigated via a proteomics approach and a controlled protein depletion experiment (D3L). A total of 193 proteins were identified. Common proteins such as pathogenesis-related protein, proteases (Nep [EC:3.4.23.12], SCP [EC:3.4.16.-]), peroxidase [EC:1.11.1.7], GDSL esterase/lipase [EC:3.1.1.-], and purple acid phosphatase [EC:3.1.3.2] were found in high abundance in the D0 pitchers and were replenished in D3L samples. This reflects their importance for biological processes upon pitcher opening. Meanwhile, prey-inducible chitinases [EC:3.2.1.14] were found in D0 but not in D3C and D3L samples, which suggests their degradation in the absence of prey. Protease activity assays demonstrated the replenishment of proteases in D3L with similar levels of proteolytic activities to that of D3C samples. This supports a feedback mechanism and signaling in the molecular regulation of endogenous protein secretion, turnover, and activity in Nepenthes pitcher fluids. Furthermore, we also discovered several new enzymes (XTH [EC:2.4.1.207], PAE [EC:3.1.1.98]) with possible functions in cell wall degradation that could contribute to the detritivory habit of N. ampullaria.

Matched MeSH terms: Plant Proteins
Fulltext Variants in genes encoding small GTPases and association with epithelial ovarian cancer susceptibility

Earp M, Tyrer JP, Winham SJ, Lin HY, Chornokur G, Dennis J, et al.

PLoS One, 2018;13(7):e0197561.
PMID: 29979793 DOI: 10.1371/journal.pone.0197561

Epithelial ovarian cancer (EOC) is the fifth leading cause of cancer mortality in American women. Normal ovarian physiology is intricately connected to small GTP binding proteins of the Ras superfamily (Ras, Rho, Rab, Arf, and Ran) which govern processes such as signal transduction, cell proliferation, cell motility, and vesicle transport. We hypothesized that common germline variation in genes encoding small GTPases is associated with EOC risk. We investigated 322 variants in 88 small GTPase genes in germline DNA of 18,736 EOC patients and 26,138 controls of European ancestry using a custom genotype array and logistic regression fitting log-additive models. Functional annotation was used to identify biofeatures and expression quantitative trait loci that intersect with risk variants. One variant, ARHGEF10L (Rho guanine nucleotide exchange factor 10 like) rs2256787, was associated with increased endometrioid EOC risk (OR = 1.33, p = 4.46 x 10-6). Other variants of interest included another in ARHGEF10L, rs10788679, which was associated with invasive serous EOC risk (OR = 1.07, p = 0.00026) and two variants in AKAP6 (A-kinase anchoring protein 6) which were associated with risk of invasive EOC (rs1955513, OR = 0.90, p = 0.00033; rs927062, OR = 0.94, p = 0.00059). Functional annotation revealed that the two ARHGEF10L variants were located in super-enhancer regions and that AKAP6 rs927062 was associated with expression of GTPase gene ARHGAP5 (Rho GTPase activating protein 5). Inherited variants in ARHGEF10L and AKAP6, with potential transcriptional regulatory function and association with EOC risk, warrant investigation in independent EOC study populations.

Matched MeSH terms: Monomeric GTP-Binding Proteins/genetics*; A Kinase Anchor Proteins/genetics*
Fulltext Expression of Ki-67, Cornulin and ISG15 in non-involved mucosal surgical margins as predictive markers for relapse in oral squamous cell carcinoma (OSCC)

Govindaraj PK, Kallarakkal TG, Mohd Zain R, Tilakaratne WM, Lew HL

PLoS One, 2021;16(12):e0261575.
PMID: 34941961 DOI: 10.1371/journal.pone.0261575

BACKGROUND: Local relapse of oral squamous cell carcinoma in non-involved mucosal surgical margins indicated possibility of field alteration in the margins, which could be predicted with certain biomarkers. The objectives were to evaluate the expression of Ki-67, Cornulin and ISG15 in non-involved mucosal surgical margins and the association of clinicopathological prognosticators with local relapse in oral squamous cell carcinoma.
METHODS: Surgical margins from the study (relapse) group (n = 23), control (non-relapse) group (n = 32) and normal oral mucosa (n = 5) were immunohistochemically stained using Ki-67, Cornulin and ISG15 antibodies. Association between expression of markers and clinicopathological prognosticators with local relapse in oral squamous cell carcinoma was analyzed statistically.
RESULTS: The study group surgical margins demonstrated significantly decreased Cornulin expression (p = 0.032). Low Cornulin expression was significantly associated with local relapse (p = 0.004) and non-tongue primary tumor (p = 0.013). Although not significantly associated with local relapse, expression of Ki-67 was significantly reduced in female patients (p = 0.041). Age above 57.5 years, Chinese & Indian ethnicity, alcohol consumption, epithelial dysplasia in surgical margins, and type III and IV patterns of invasion of tumor were also significantly related to local relapse. Regression analysis showed low expression of Cornulin (p = 0.018), and increased patient's age (p = 0.008) were predictors of local relapse in oral squamous cell carcinoma, with 34-fold risk and 18-fold risk, respectively. Expression of Ki-67 and ISG15 did not show significant association with local relapse in oral squamous cell carcinoma.
CONCLUSION: Low expression of Cornulin is an independent predictor of relapse in oral squamous cell carcinoma.

Matched MeSH terms: Membrane Proteins/analysis*; Neoplasm Proteins/analysis*
Fulltext Genome-wide association analyses identify three new susceptibility loci for primary angle closure glaucoma

Vithana EN, Khor CC, Qiao C, Nongpiur ME, George R, Chen LJ, et al.

Nat Genet, 2012 Oct;44(10):1142-1146.
PMID: 22922875 DOI: 10.1038/ng.2390

Primary angle closure glaucoma (PACG) is a major cause of blindness worldwide. We conducted a genome-wide association study including 1,854 PACG cases and 9,608 controls across 5 sample collections in Asia. Replication experiments were conducted in 1,917 PACG cases and 8,943 controls collected from a further 6 sample collections. We report significant associations at three new loci: rs11024102 in PLEKHA7 (per-allele odds ratio (OR)=1.22; P=5.33×10(-12)), rs3753841 in COL11A1 (per-allele OR=1.20; P=9.22×10(-10)) and rs1015213 located between PCMTD1 and ST18 on chromosome 8q (per-allele OR=1.50; P=3.29×10(-9)). Our findings, accumulated across these independent worldwide collections, suggest possible mechanisms explaining the pathogenesis of PACG.

Matched MeSH terms: Carrier Proteins/genetics*; Repressor Proteins/genetics
Comparative nutritional value of Jatropha curcas protein isolate and soy protein isolate in common carp

Nepal S, Kumar V, Makkar HPS, Stadtlander T, Romano N, Becker K

Fish Physiol Biochem, 2018 Feb;44(1):143-162.
PMID: 28900838 DOI: 10.1007/s10695-017-0420-x

Jatropha seed cake (JSC) is an excellent source of protein but does contain some antinutritional factors (ANF) that can act as toxins and thus negatively affect the growth and health status of fish. While this can limit the use of JSC, detoxified Jatropha protein isolate (DJPI) may be a better option. An 8-week study was performed to evaluate dietary DJPI to common carp Cyprinus carpio. Five iso-nitrogenous diets (crude protein of 38%) were formulated that consisted of a C ontrol (fish meal (FM) based protein), J 50 or J 75 (50 and 75% of FM protein replaced by DJPI), and S 50 or S 75 (50 and 75% of FM protein replaced by soy protein isolate, SPI) and fed to triplicate groups of 75 carp fingerlings (75; av. wt. ± SD; 11.4 ± 0.25 g). The growth, feeding efficiencies, digestibility, plasma biochemistry, and intestinal enzymes were measured. Results showed that growth performance of fish fed the S 75- or DJPI-based diets were not significantly different from those fed the C ontrol diet, while carp fed the S 50 had significantly better growth than the J 75 diet. Fish fed the J 75 diet had significantly lower protein and lipid digestibility as well as significantly lower intestinal amylase and protease activities than all other groups. However, all plant protein-based diets led to significantly higher crude protein, crude lipid, and gross energy in the body of common carp compared to the control treatment. Plasma cholesterol and creatinine significantly decreased in the plant protein fed groups, although plasma triglyceride as well as the red blood cells count, hematocrit, albumin, globulin, total plasma protein, and lysozyme activity were higher in plant protein fed groups compared to FM fed group. White blood cells, hemoglobulin concentration, alkaline phosphatase and alanine transaminase activities, and glucose level in blood did not differ significantly among treatments. The results suggest that the DJPI is non-toxic to carp and can be used to replace FM in the diets of common carp up to 75%, but further research to potentially reduce some inherent ANF within this protein source, such as non-starch polysaccharides, may improve nutrient utilization.

Matched MeSH terms: Dietary Proteins*; Plant Proteins*
Drug-like dietary vanilloids induce anticancer activity through proliferation inhibition and regulation of bcl-related apoptotic proteins

Mai CW, Kang YB, Nadarajah VD, Hamzah AS, Pichika MR

Phytother Res, 2018 Jun;32(6):1108-1118.
PMID: 29464796 DOI: 10.1002/ptr.6051

In this study, a series of 20 structurally similar vanilloids (Vn) were tested for their antiproliferative effects against 12 human cancer cells: human breast (MCF-7 and MDA-MB-231), cervical (HeLa), ovarian (Caov-3), lung (A549), liver (HepG2), colorectal (HT-29 and HCT116), nasopharyngeal (CNE-1 and HK-1), and leukemic (K562 and CEM-SS) cancer cells. Among all the tested vanilloids, Vn16 (6-shogaol) exhibited the most potent cytotoxic effects against human colorectal cancer cells (HT-29). The apoptotic induction effects exhibited by Vn16 on HT-29 cells were confirmed using dual staining fluorescence microscopy and enzyme-linked immunosorbent assay. The effects of Vn16 on regulation of 43 apoptotic-related markers were determined in HT-29. The results suggested that 8 apoptotic markers (caspase 8, BAD, BAX, second mitochondrial-derived activator, caspase 3, survivin, bcl-2, and cIAP-2) were either upregulated or downregulated. These results further support the chemopreventive properties of foods that contain vanilloids.

Matched MeSH terms: Proto-Oncogene Proteins c-bcl-2/metabolism*; Inhibitor of Apoptosis Proteins/metabolism*
Fulltext The structure of a major surface antigen SAG19 from Eimeria tenella unifies the Eimeria SAG family

Ramly NZ, Dix SR, Ruzheinikov SN, Sedelnikova SE, Baker PJ, Chow YP, et al.

Commun Biol, 2021 03 19;4(1):376.
PMID: 33742128 DOI: 10.1038/s42003-021-01904-w

In infections by apicomplexan parasites including Plasmodium, Toxoplasma gondii, and Eimeria, host interactions are mediated by proteins including families of membrane-anchored cysteine-rich surface antigens (SAGs) and SAG-related sequences (SRS). Eimeria tenella causes caecal coccidiosis in chickens and has a SAG family with over 80 members making up 1% of the proteome. We have solved the structure of a representative E. tenella SAG, EtSAG19, revealing that, despite a low level of sequence similarity, the entire Eimeria SAG family is unified by its three-layer αβα fold which is related to that of the CAP superfamily. Furthermore, sequence comparisons show that the Eimeria SAG fold is conserved in surface antigens of the human coccidial parasite Cyclospora cayetanensis but this fold is unrelated to that of the SAGs/SRS proteins expressed in other apicomplexans including Plasmodium species and the cyst-forming coccidia Toxoplasma gondii, Neospora caninum and Besnoitia besnoiti. However, despite having very different structures, Consurf analysis showed that Eimeria SAG and Toxoplasma SRS families each exhibit marked hotspots of sequence hypervariability that map to their surfaces distal to the membrane anchor. This suggests that the primary and convergent purpose of the different structures is to provide a platform onto which sequence variability can be imposed.

Matched MeSH terms: Protozoan Proteins/genetics; Protozoan Proteins/metabolism*; Protozoan Proteins/chemistry
Amyloid precursor protein in Alzheimer's disease

Maurya R, Bhattacharjee G, Khambhati K, Gohil N, Singh P, Mani I, et al.

Prog Mol Biol Transl Sci, 2023;196:261-270.
PMID: 36813361 DOI: 10.1016/bs.pmbts.2022.09.006

Amyloid precursor protein (APP) is a membrane protein expressed in several tissues. The occurrence of APP is predominant in synapses of nerve cells. It acts as a cell surface receptor and plays a vital role as a regulator of synapse formation, iron export and neural plasticity. It is encoded by the APP gene that is regulated by substrate presentation. APP is a precursor protein activated by proteolytic cleavage and thereby generating amyloid beta (Aβ) peptides which eventually form amyloid plaques that accumulate in Alzheimer's disease patients' brains. In this chapter, we highlight basic mechanism, structure, expression patterns and cleavage of amyloid plaques, and its diagnosis and potential treatment for Alzheimer's disease.

Matched MeSH terms: Membrane Proteins
Fulltext Neonatal intrahepatic cholestasis caused by citrin deficiency in two Malaysian siblings: outcome at one year of life

Thong MK, Boey CC, Sheng JS, Ushikai M, Kobayashi K

Singapore Med J, 2010 Jan;51(1):e12-4.
PMID: 20200759

We report two Malaysian siblings with neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD). The younger sibling, a six-month-old Chinese girl, presented with prolonged neonatal jaundice, and was investigated for biliary atresia. Urine metabolic screen showed the presence of urinary-reducing sugars, and she was treated with a lactose-free formula. NICCD was suspected based on the clinical history, examination and presence of urinary citrulline. Mutation study of the SLC25A13 gene showed the compound heterozygotes, 851del4 and IVS16ins3kb, which confirmed the diagnosis of NICCD in the patient and her three-year-old female sibling, who also had unexplained neonatal cholestasis. Long-term dietary advice, medical surveillance and genetic counselling were provided to the family. The diagnosis of NICCD should be considered in infants with unexplained prolonged jaundice. DNA-based genetic testing of the SLC25A13 gene may be performed to confirm the diagnosis retrospectively. An awareness of this condition may help in early diagnosis using appropriate metabolic and biochemical investigations, thus avoiding invasive investigations in infants with neonatal cholestasis caused by NICCD.

Matched MeSH terms: Calcium-Binding Proteins/deficiency*; Mitochondrial Membrane Transport Proteins/genetics*
Fulltext Calculated parameters for the diagnosis of Wilson disease

Zulkufli NS, Sthaneshwar P, Chan WK

Singapore Med J, 2023 Mar;64(3):188-195.
PMID: 35139628 DOI: 10.11622/smedj.2022019

INTRODUCTION: The diagnosis of Wilson disease (WD) is plagued by biochemical and clinical uncertainties. Thus, calculated parameters have been proposed. This study aimed to: (a) compare the diagnostic values of non-caeruloplasmin copper (NCC), NCC percentage (NCC%), copper-caeruloplasmin ratio (CCR) and adjusted copper in WD; and (b) derive and evaluate a discriminant function in diagnosing WD.
METHODS: A total of 213 subjects across all ages who were investigated for WD were recruited. WD was confirmed in 55 patients, and the rest were WD free. Based on serum copper and caeruloplasmin values, NCC, NCC%, CCR and adjusted copper were calculated for each subject. A function was derived using discriminant analysis, and the cut-off value was determined through receiver operating characteristic analysis. Classification accuracy was found by cross-tabulation.
RESULTS: Caeruloplasmin, total copper, NCC, NCC%, CCR, adjusted copper and discriminant function were significantly lower in WD compared to non-WD. Discriminant function showed the best diagnostic specificity (99.4%), sensitivity (98.2%) and classification accuracy (99.1%). Caeruloplasmin levels <0.14 g/L showed higher accuracy than the recommended 0.20 g/L cut-off value (97.7% vs. 87.8%). Similarly, molar NCC below the European cut-off of 1.6 umol/L showed higher accuracy than the American cut-off of 3.9 umol/L (80.3% vs. 59.6%) (P < 0.001). NCC%, mass NCC, CCR and adjusted copper showed poorer performances.
CONCLUSION: Discriminant function differentiates WD from non-WD with excellent specificity, sensitivity and accuracy. Performance of serum caeruloplasmin <0.14 g/L was better than that of <0.20 g/L. NCC, NCC%, CCR and adjusted copper are not helpful in diagnosing WD.

Matched MeSH terms: Repressor Proteins
Fulltext Cytoprotective Role of Omentin Against Oxidative Stress-Induced Vascular Endothelial Cells Injury

Binti Kamaruddin NA, Fong LY, Tan JJ, Abdullah MNH, Singh Cheema M, Bin Yakop F, et al.

Molecules, 2020 May 29;25(11).
PMID: 32485974 DOI: 10.3390/molecules25112534

Endothelial cell injury caused by reactive oxygen species (ROS) plays a critical role in the pathogenesis of cardiovascular diseases. Omentin, an adipocytokine that is abundantly expressed in visceral fat tissue, has been reported to possess anti-inflammatory and antidiabetic properties. However, endothelial protective effects of omentin against oxidative stress remain unclear. This study aimed to evaluate the protective effect of omentin against hydrogen peroxide (H2O2)-induced cell injury in human umbilical vein endothelial cells (HUVECs). Cytotoxicity and cytoprotective effects of omentin were evaluated using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The apoptotic activity of HUVECs was detected using Annexin-V/PI and Hoechst 33258 staining methods. Antioxidant activity of omentin was evaluated by measuring both reactive oxygen species (ROS) levels and glutathione peroxidase (GPx) activity. No cytotoxicity effect was observed in HUVECs treated with omentin alone at concentrations of 150 to 450 ng/ml. MTT assay showed that omentin significantly prevented the cell death induced by H2O2 (p < 0.001). Hoechst staining and flow cytometry also revealed that omentin markedly prevented H2O2-induced apoptosis. Moreover, omentin not only significantly inhibited ROS production (p < 0.01) but also significantly (p < 0.01) increased GPx activity in HUVECs. In conclusion, our data suggest that omentin may protect HUVECs from injury induced by H2O2.

Matched MeSH terms: Recombinant Proteins/pharmacology; GPI-Linked Proteins/pharmacology
Method development for analysis of proteins extracted from the leaves of Orthosiphon aristatus

Koay SY, Gam LH

J Chromatogr B Analyt Technol Biomed Life Sci, 2011 Jul 15;879(22):2179-83.
PMID: 21689998 DOI: 10.1016/j.jchromb.2011.05.041

Orthosiphon aristatus is a traditionally used medicinal plant. In order to study the proteome of the plant, we have developed a simple plant protein extraction method by direct extraction of protein using a modified 2D-gel compatible tris-sucrose buffer followed by a double TCA-acetone precipitation. This method omitted the use of toxic phenol which is widely used in the studies of plants proteins. Moreover, it shortens the lengthy extraction procedure of phenol extraction and back-extraction method and therefore reduced the extraction time (by 2h) while increased in protein yields (by 50%). Comparison of the 2D-gel images of the two extracts revealed that >60 extra protein spots were detected in the extract of our current method. The method was applied on the leaves of O. aristatus collected from six geographical areas in Malaysia. The correlation coefficient of each replicate gels from the six areas ranged from 0.70 to 0.90 indicating good reproducibility of the method.

Matched MeSH terms: Plant Proteins/analysis; Plant Proteins/isolation & purification; Plant Proteins/chemistry*
Identification of dual active sites in Caenorhabditis elegans GANA-1 protein: an ortholog of the human α-GAL a and α-NAGA enzymes

Cheong CSY, Khan SU, Ahmed N, Narayanan K

J Biomol Struct Dyn, 2023 Jul;41(11):5261-5276.
PMID: 35694994 DOI: 10.1080/07391102.2022.2084162

Fabry disease (FD) is caused by a defective α-galactosidase A (α-GAL A) enzyme responsible for breaking down globotriaosylceramide (Gb3). To develop affordable therapeutics, more effort is needed to obtain insights into the underlying mechanism of FD and understanding human α-GAL A structure and function in related animal models. We adopted C. elegans as a model to elucidate the sequence and 3D structure of its GANA-1 enzyme and compared it to human α-GAL A. We constructed GANA-1 3D structure by homology modelling and validated the quality of the predicted GANA-1 structure, followed by computational docking of human ligands. The GANA-1 protein shared sequence similarities up to 42.1% with the human α-GAL A in silico and had dual active sites. GANA-1 homology modelling showed that 11 out of 13 amino acids in the first active site of GANA-1 protein overlapped with the human α-GAL A active site, indicating the prospect for substrate cross-reaction. Computational molecular docking using human ligands like Gb3 (first pocket), 4-nitrophenyl-α-D-galactopyranoside (second pocket), α-galactose (second pocket), and N-acetyl-D-galactosamine (second pocket) showed negative binding energy. This revealed that the ligands were able to bind within both GANA-1 active sites, mimicking the human α-GAL A and α-NAGA enzymes. We identified human compounds with adequate docking scores, predicting robust interactions with the GANA-1 active site. Our data suggested that the C. elegans GANA-1 enzyme may possess structural and functional similarities to human α-GAL A, including an intrinsic capability to metabolize Gb3 deposits.Communicated by Ramaswamy H. Sarma.

Matched MeSH terms: Proteins
Ectopic expression of a Musa acuminata root hair defective 3 (MaRHD3) in Arabidopsis enhances drought tolerance

Wong GR, Mazumdar P, Lau SE, Harikrishna JA

J Plant Physiol, 2018 Dec;231:219-233.
PMID: 30292098 DOI: 10.1016/j.jplph.2018.09.018

Genetic improvement is an important approach for crop improvement towards yield stability in stress-prone areas. Functional analysis of candidate stress response genes can provide key information to allow the selection and modification of improved crop varieties. In this study, the constitutive expression of a banana cDNA, MaRHD3 in Arabidopsis improved the ability of transgenic lines to adapt to drought conditions. Transgenic Arabidopsis plants expressing MaRHD3 had roots with enhanced branching and more root hairs when challenged with drought stress. The MaRHD3 plants had higher biomass accumulation, higher relative water content, higher chlorophyll content and an increase in activity of reactive oxygen species (ROS) scavenging enzymes; SOD, CAT, GR, POD and APX with reduced water loss rates compared to control plants. The analysis of oxidative damage indicated lower cell membrane damage in transgenic lines compared to control plants. These findings, together with data from higher expression of ABF-3 and higher ABA content of drought-stressed transgenic MaRHD3 expressing plants, support the involvement of the ABA signal pathway and ROS scavenging enzyme systems in MaRHD3 mediated drought tolerance.

Matched MeSH terms: Plant Proteins/genetics; Plant Proteins/metabolism; Plant Proteins/physiology
Fulltext Methods for Systematic Identification of Membrane Proteins for Specific Capture of Cancer-Derived Extracellular Vesicles

Zaborowski MP, Lee K, Na YJ, Sammarco A, Zhang X, Iwanicki M, et al.

Cell Rep, 2019 Apr 02;27(1):255-268.e6.
PMID: 30943406 DOI: 10.1016/j.celrep.2019.03.003

Analysis of cancer-derived extracellular vesicles (EVs) in biofluids potentially provides a source of disease biomarkers. At present there is no procedure to systematically identify which antigens should be targeted to differentiate cancer-derived from normal host cell-derived EVs. Here, we propose a computational framework that integrates information about membrane proteins in tumors and normal tissues from databases: UniProt, The Cancer Genome Atlas, the Genotype-Tissue Expression Project, and the Human Protein Atlas. We developed two methods to assess capture of EVs from specific cell types. (1) We used palmitoylated fluorescent protein (palmtdTomato) to label tumor-derived EVs. Beads displaying antibodies of interest were incubated with conditioned medium from palmtdTomato-expressing cells. Bound EVs were quantified using flow cytometry. (2) We also showed that membrane-bound Gaussia luciferase allows the detection of cancer-derived EVs in blood of tumor-bearing animals. Our analytical and validation platform should be applicable to identify antigens on EVs from any tumor type.

Matched MeSH terms: Membrane Proteins/metabolism*; Green Fluorescent Proteins/metabolism
Fulltext Site-specific imprinting of dengue virus non-structural 1 antigen on a polydopamine-based sensing film for early detection and prognosis of dengue

Lim HJ, Saha T, Ooi CW

Talanta, 2024 Feb 01;268(Pt 2):125376.
PMID: 37951180 DOI: 10.1016/j.talanta.2023.125376

Serum levels of dengue virus (DENV) non-structural 1 (NS1) antigen can serve as a valuable prognostic indicator of severe dengue infections. A quartz crystal microbalance (QCM)-based biosensor with a biomimetic recognition element was designed to quantitatively detect DENV NS1 as an early disease biomarker. To mitigate the reliance on costly viral antigens during the molecular imprinting process, a synthetic peptide mimicking a DENV NS1 epitope was used as a surrogate template for the synthesis of an epitope-imprinted polydopamine (EMIPDA) sensing film on the biosensor surface. The maximal frequency shift for DENV NS1 was obtained with an EMIPDA film synthesised using 5 mg mL-1 of dopamine monomer and 0.5 mg mL-1 of peptide template. The EMIPDA-QCM biosensor achieved low detection and quantitation limits of 0.091 μg mL-1 and 0.436 μg mL-1, respectively, allowing acute-phase detection of dengue and prognosis of the disease progression. The EMIPDA-QCM biosensor exhibited remarkable selectivity with up to 68-fold larger frequency responses towards DENV NS1 compared to a major serum protein. The site-specific imprinting approach not only enhanced the biosensing performance but also enabled a 26-fold cost reduction for biosensor functionalisation, providing a cost-effective strategy for label-free biosensing of the dengue biomarker via the biopolymer film.

Matched MeSH terms: Viral Nonstructural Proteins

Filters

Please provide feedback to Administrator ([email protected])

External Links