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  1. Intracellular capacitive effects of polarized proteins in dendrites
    Poznanski RR, Cacha LA
    J Integr Neurosci, 2012 Dec;11(4):417-37.
    PMID: 23351050 DOI: 10.1142/S0219635212500264
    Passive dendrites become active as a result of electrostatic interactions by dielectric polarization in proteins in a segment of a dendrite. The resultant nonlinear cable equation for a cylindrical volume representation of a dendritic segment is derived from Maxwell's equations under assumptions: (i) the electric field is restricted longitudinally along the cable length; (ii) extracellular isopotentiality; (iii) quasi-electrostatic conditions; (iv) isotropic membrane and homogeneous medium with constant conductivity; and (v) protein polarization contributes to intracellular capacitive effects through a well defined nonlinear capacity-voltage characteristic; (vi) intracellular resistance and capacitance in parallel are connected to the membrane in series. Under the above hypotheses, traveling wave solutions of the cable equation are obtained as propagating fronts of electrical excitation associated with capacitive charge-equalization and dispersion of continuous polarization charge densities in an Ohmic cable. The intracellular capacitative effects of polarized proteins in dendrites contribute to the conduction process.
    Matched MeSH terms: Proteins/physiology*
  2. Fulltext Erosive potential of commonly used beverages, medicated syrup, and their effects on dental enamel with and without restoration: An in vitro study
    Trivedi K, Bhaskar V, Ganesh M, Venkataraghavan K, Choudhary P, Shah S, et al.
    J Pharm Bioallied Sci, 2015 Aug;7(Suppl 2):S474-80.
    PMID: 26538901 DOI: 10.4103/0975-7406.163508
    AIM: This study evaluates erosive potential of commonly used beverages, medicated syrup, and their effects on dental enamel with and without restoration in vitro.

    MATERIALS AND METHODS: Test medias used in this study included carbonated beverage, noncarbonated beverage, high-energy sports drink medicated cough syrup, distilled water as the control. A total of 110 previously extracted human premolar teeth were selected for the study. Teeth were randomly divided into two groups. Test specimens were randomly distributed to five beverages groups and comprised 12 specimens per group. Surface roughness (profilometer) readings were performed at baseline and again, following immersion for 14 days (24 h/day). Microleakage was evaluated. The results obtained were analyzed for statistical significance using SPSS-PC package using the multiple factor ANOVA at a significance level of P < 0.05. Paired t-test, Friedman test ranks, and Wilcoxon signed ranks test.

    RESULTS: For surface roughness high-energy sports drink and noncarbonated beverage showed the highly significant difference with P values of 0.000 and 0.000, respectively compared to other test media. For microleakage high-energy sports drink had significant difference in comparison to noncarbonated beverage (P = 0.002), medicated syrup (P = 0.000), and distilled water (P = 0.000).

    CONCLUSION: High-energy sports drink showed highest surface roughness value and microleakage score among all test media and thus greater erosive potential to enamel while medicated syrup showed least surface roughness value and microleakage among all test media.

    Matched MeSH terms: Nerve Tissue Proteins; RNA-Binding Proteins
  3. Fulltext Intermaxillary tooth size discrepancy in a Pakistani population: A stereomicroscope versus digital caliper
    Shahid F, Alam MK, Khamis MF
    Eur J Dent, 2016 4 21;10(2):176-182.
    PMID: 27095892 DOI: 10.4103/1305-7456.178299
    OBJECTIVE: Comprehensive diagnosis and treatment planning are essential in a successful orthodontic practice. The purpose of this study is to determine and compare intermaxillary tooth size discrepancy (IMTSD) using traditional digital caliper (DC) measurement on plaster dental models and stereomicroscopic digital dental models (SM).

    MATERIALS AND METHODS: The samples were randomly selected from different states of Pakistan. Total 7168 variables were measured on plaster dental casts (128) and SM digital dental models (128) according to the selection criteria. For IMTSD, the 6 variable measured as for anterior tooth size (maxilla, mandibular), overall tooth size (maxilla, mandibular), Bolton's anterior ratios (BAR), and Bolton's overall ratios (BOR). The independent t-test and ANOVA were used for statistical analyses.

    RESULTS: Significant sexual disparities in the sum of anterior tooth size and overall tooth size via DC and SM methods. No significant sexual disparities for BAR and BOR. No statistically significant differences were found in BAR and BOR between DC and SM. No significant differences were found on IMTSD ratio among different arch length and arch perimeters groups.

    CONCLUSIONS: Norms were developed based on DC and SM for IMTSD. Sexual disparities were observed in the sum of teeth size. However, no significant differences in BAR and BOR for IMTSD between the two methods.

    Matched MeSH terms: Nerve Tissue Proteins; RNA-Binding Proteins
  4. Current trends in endotoxin detection and analysis of endotoxin-protein interactions
    Dullah EC, Ongkudon CM
    Crit Rev Biotechnol, 2017 Mar;37(2):251-261.
    PMID: 26863480 DOI: 10.3109/07388551.2016.1141393
    Endotoxin is a type of pyrogen that can be found in Gram-negative bacteria. Endotoxin can form a stable interaction with other biomolecules thus making its removal difficult especially during the production of biopharmaceutical drugs. The prevention of endotoxins from contaminating biopharmaceutical products is paramount as endotoxin contamination, even in small quantities, can result in fever, inflammation, sepsis, tissue damage and even lead to death. Highly sensitive and accurate detection of endotoxins are keys in the development of biopharmaceutical products derived from Gram-negative bacteria. It will facilitate the study of the intermolecular interaction of an endotoxin with other biomolecules, hence the selection of appropriate endotoxin removal strategies. Currently, most researchers rely on the conventional LAL-based endotoxin detection method. However, new methods have been and are being developed to overcome the problems associated with the LAL-based method. This review paper highlights the current research trends in endotoxin detection from conventional methods to newly developed biosensors. Additionally, it also provides an overview of the use of electron microscopy, dynamic light scattering (DLS), fluorescence resonance energy transfer (FRET) and docking programs in the endotoxin-protein analysis.
    Matched MeSH terms: Proteins/metabolism
  5. Proteomics of Important Food Crops in the Asia Oceania Region: Current Status and Future Perspectives
    Chakraborty S, Salekdeh GH, Yang P, Woo SH, Chin CF, Gehring C, et al.
    J Proteome Res, 2015 Jul 2;14(7):2723-44.
    PMID: 26035454 DOI: 10.1021/acs.jproteome.5b00211
    In the rapidly growing economies of Asia and Oceania, food security has become a primary concern. With the rising population, growing more food at affordable prices is becoming even more important. In addition, the predicted climate change will lead to drastic changes in global surface temperature and changes in rainfall patterns that in turn will pose a serious threat to plant vegetation worldwide. As a result, understanding how plants will survive in a changing climate will be increasingly important. Such challenges require integrated approaches to increase agricultural production and cope with environmental threats. Proteomics can play a role in unraveling the underlying mechanisms for food production to address the growing demand for food. In this review, the current status of food crop proteomics is discussed, especially in regard to the Asia and Oceania regions. Furthermore, the future perspective in relation to proteomic techniques for the important food crops is highlighted.
    Matched MeSH terms: Plant Proteins/metabolism*
  6. Fulltext The Curcumin Analogue 1,5-Bis(2-hydroxyphenyl)-1,4-pentadiene-3-one Induces Apoptosis and Downregulates E6 and E7 Oncogene Expression in HPV16 and HPV18-Infected Cervical Cancer Cells
    Paulraj F, Abas F, Lajis NH, Othman I, Hassan SS, Naidu R
    Molecules, 2015;20(7):11830-60.
    PMID: 26132907 DOI: 10.3390/molecules200711830
    In an effort to study curcumin analogues as an alternative to improve the therapeutic efficacy of curcumin, we screened the cytotoxic potential of four diarylpentanoids using the HeLa and CaSki cervical cancer cell lines. Determination of their EC50 values indicated relatively higher potency of 1,5-bis(2-hydroxyphenyl)-1,4-pentadiene-3-one (MS17, 1.03 ± 0.5 μM; 2.6 ± 0.9 μM) and 1,5-bis(4-hydroxy-3-methoxyphenyl)-1,4-pentadiene-3-one (MS13, 2.8 ± 0.4; 6.7 ± 2.4 μM) in CaSki and HeLa, respectively, with significantly greater growth inhibition at 48 and 72 h of treatment compared to the other analogues or curcumin. Based on cytotoxic and anti-proliferative activity, MS17 was selected for comprehensive apoptotic studies. At 24 h of treatment, fluorescence microscopy detected that MS17-exposed cells exhibited significant morphological changes consistent with apoptosis, corroborated by an increase in nucleosomal enrichment due to DNA fragmentation in HeLa and CaSki cells and activation of caspase-3 activity in CaSki cells. Quantitative real-time PCR also detected significant down-regulation of HPV18- and HPV16-associated E6 and E7 oncogene expression following treatment. The overall data suggests that MS17 treatment has cytotoxic, anti-proliferative and apoptosis-inducing potential in HPV-positive cervical cancer cells. Furthermore, its role in down-regulation of HPV-associated oncogenes responsible for cancer progression merits further investigation into its chemotherapeutic role for cervical cancer.
    Matched MeSH terms: DNA-Binding Proteins/genetics*; Oncogene Proteins, Viral/genetics*; Repressor Proteins/genetics*; Papillomavirus E7 Proteins/genetics*
  7. Preparation and characterisation of nanoliposomes containing winged bean seeds bioactive peptides
    Chay SY, Tan WK, Saari N
    J Microencapsul, 2015;32(5):488-95.
    PMID: 26079597 DOI: 10.3109/02652048.2015.1057250
    The aim of this study was to produce and characterise nanosize liposomes containing bioactive peptides with antioxidative and ACE-inhibitory properties, derived from winged bean seeds (WBS) protein. WBS powder was papain-proteolysed, at 70 °C and pH 6.5 for six hours, followed by encapsulation via a solvent-free heating method. The results showed that the WBS proteolysate was successfully incorporated into spherical, unilamellar liposomal particles, with particle diameter, polydispersity index, zeta potential and encapsulation efficiency of 193.3 ± 0.12 nm, 0.4 ± 0.02 (unit less), -70.5 ± 0.30 mV and 27.6 ± 1.17%, respectively. It also demonstrated good storage stability over eight weeks at 4 °C, indicated by slight increment (15.1%) in particle size and a zeta potential only weaker by 17.2% at the end of the study period. These results suggested the feasibility of entrapping water soluble peptides in hydrophobic liposomal system that, upon optimisation, has the potential to act as bioactive food ingredient.
    Matched MeSH terms: Seed Storage Proteins/chemistry*
  8. Fulltext Biotechnological Aspects and Perspective of Microbial Keratinase Production
    Gopinath SC, Anbu P, Lakshmipriya T, Tang TH, Chen Y, Hashim U, et al.
    Biomed Res Int, 2015;2015:140726.
    PMID: 26180780 DOI: 10.1155/2015/140726
    Keratinases are proteolytic enzymes predominantly active when keratin substrates are available that attack disulfide bridges in the keratin to convert them from complex to simplified forms. Keratinases are essential in preparation of animal nutrients, protein supplements, leather manufacture, textile processing, detergent formulation, feather meal processing for feed and fertilizer, the pharmaceutical and biomedical industries, and waste management. Accordingly, it is necessary to develop a method for continuous production of keratinase from reliable sources that can be easily managed. Microbial keratinase is less expensive than conventionally produced keratinase and can be obtained from fungi, bacteria, and actinomycetes. In this overview, the expansion of information about microbial keratinases and important considerations in keratinase production are discussed.
    Matched MeSH terms: Bacterial Proteins/chemistry*
  9. Cloning and expression of the phosphoprotein gene of Newcastle disease virus in Escherichia coli
    Kho CL, Tan WS, Yusoff K
    J. Biochem. Mol. Biol. Biophys., 2002 Apr;6(2):117-21.
    PMID: 12186767
    The phosphoprotein (P) gene of a heat stable Newcastle disease virus (NDV) was cloned, sequenced and expressed in Escherichia coli. SDS-PAGE analysis of the recombinant P protein (395 amino acids) and a C-terminal extension derivative (424 amino acids), gave rise to two distinct protein bands with molecular masses of approximately 53-55 and 56-58 kDa, respectively, which are approximately 26-30% heavier than those calculated from the deduced amino acid sequences. The differences in molecular mass on SDS-PAGE are thought to be attributed to the acidic nature of the P protein (pI=6.27) and also the different degrees of phosphorylation in the prokaryotic cell. Amino acid sequence comparison of the P protein among the published NDV strains showed that they were highly conserved particularly at the putative phosphorylation sites.
    Matched MeSH terms: Recombinant Proteins/biosynthesis; Recombinant Proteins/genetics; Recombinant Proteins/chemistry; Viral Proteins/biosynthesis; Viral Proteins/genetics*; Viral Proteins/chemistry
  10. A direct 3H-radioligand assay for serum progesterone compared with an assay involving extraction of serum
    Raman IA, Satgunasingam N
    Malays J Pathol, 1993 Dec;15(2):115-8.
    PMID: 8065171
    The direct assay of serum progesterone after denaturation of the binding proteins was investigated. 50ul of patients' serum was diluted with 750ul phosphate buffer (0.05M, pH 7.4) and heated to 65 degrees C for 20 minutes. After cooling, 300ul of the treated serum was reacted with a rabbit antiserum to progesterone-11 alpha-hemicuccinyl-bovine serum albumin conjugate (Bioclin, U.K) and 1,2,6,7, tritium labelled progesterone. Separation of bound and free fractions was achieved with dextran coated charcoal. The method correlated well (r = 0.98) with an established method involving ether extraction of progesterone prior to assay. The mean sensitivity was 2.01 nmol/L (range 1.90-2.23nmol/L). The proposed method considerably shortens assay time and removes a tedious and imprecise stage in the conventional method involving extraction of serum.
    Matched MeSH terms: Blood Proteins/analysis*
  11. Natural cryptic autoantibodies
    Cheng HM
    Autoimmunity, 1998;27(2):99-108.
    PMID: 9583741
    Matched MeSH terms: Blood Proteins/immunology
  12. A false-positive result with the American Society for Testing and Materials D5712-95 test method for protein given by a common vulcanization accelerator
    Chen SF, Teoh SC, Porter M
    J Allergy Clin Immunol, 1997 Nov;100(5):713-4.
    PMID: 9389305
    Matched MeSH terms: Proteins/analysis
  13. The red cell 'X'-protein system in goats: evidence for a third allele in a Malaysian breed
    Hasima N, Dhaliwal SS, Mukherjee TK
    Anim. Genet., 1988;19(1):37-41.
    PMID: 3377277
    Genetic polymorphism of the 'X'-protein in red cells from Malaysian Katjang goats was demonstrated by starch gel electrophoresis at pH 7.3. Two new phenotypes were observed, suggesting that one new allele is involved. A new nomenclature for the 'X'-protein system in goats is proposed.
    Matched MeSH terms: Blood Proteins/genetics*
  14. Fulltext Mechanism of cholesterol gallstone formation
    Abu Bakar MA
    Med J Malaysia, 1987 Dec;42(4):290-3.
    PMID: 3331409
    Matched MeSH terms: Proteins/metabolism
  15. Solubility, immunogenicity and physical properties of the nucleocapsid protein of Nipah virus produced in Escherichia coli
    Tan WS, Ong ST, Eshaghi M, Foo SS, Yusoff K
    J Med Virol, 2004 May;73(1):105-12.
    PMID: 15042656
    The nucleocapsid (N) protein of Nipah virus (NiV) can be produced in three Escherichia coli strains [TOP10, BL21(DE3) and SG935] under the control of trc promoter. However, most of the product existed in the form of insoluble inclusion bodies. There was no improvement in the solubility of the product when this protein was placed under the control of T7 promoter. However, the solubility of the N protein was significantly improved by lowering the growth temperature of E. coli BL21(DE3) cell cultures. Solubility analysis of N- and C-terminally deleted mutants revealed that the full-length N protein has the highest solubility. The soluble N protein could be purified efficiently by sucrose gradient centrifugation and nickel affinity chromatography. Electron microscopic analysis of the purified product revealed that the N protein assembled into herringbone-like particles of different lengths. The C-terminal end of the N protein contains the major antigenic region when probed with antisera from humans and pigs infected naturally.
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/immunology; Recombinant Proteins/chemistry; Nucleocapsid Proteins/genetics; Nucleocapsid Proteins/immunology*; Nucleocapsid Proteins/chemistry*
  16. Fulltext S-acylation regulates the trafficking and stability of the unconventional Q-SNARE STX19
    Ampah KK, Greaves J, Shun-Shion AS, Asnawi AW, Lidster JA, Chamberlain LH, et al.
    J Cell Sci, 2018 10 22;131(20).
    PMID: 30254024 DOI: 10.1242/jcs.212498
    STX19 is an unusual Qa-SNARE as it lacks a C-terminal transmembrane domain. However, it is efficiently targeted to post-Golgi membranes. Here, we set out to determine the intracellular localisation of endogenous STX19 and elucidate the mechanism by which it is targeted to membranes. We have found that a pool of STX19 is localised to tubular recycling endosomes where it colocalises with MICAL-L1 and Rab8 (which has Rab8a and Rab8b forms). Using a combination of genetic, biochemical and cell-based approaches, we have identified that STX19 is S-acylated at its C-terminus and is a substrate for several Golgi-localised S-acyltransferases, suggesting that STX19 is initially S-acylated at the Golgi before trafficking to the plasma membrane and endosomes. Surprisingly, we have found that S-acylation is a key determinant in targeting STX19 to tubular recycling endosomes, suggesting that S-acylation may play a general role in directing proteins to this compartment. In addition, S-acylation also protects STX19 from proteosomal degradation, indicating that S-acylation regulates the function of STX19 at multiple levels.This article has an associated First Person interview with the first author of the paper.
    Matched MeSH terms: Q-SNARE Proteins/metabolism*
  17. Biochemical Characterization of the Cytochrome P450 CYP107CB2 from Bacillus lehensis G1
    Ang SS, Salleh AB, Chor LT, Normi YM, Tejo BA, Rahman MBA, et al.
    Protein J, 2018 04;37(2):180-193.
    PMID: 29508210 DOI: 10.1007/s10930-018-9764-z
    The bioconversion of vitamin D3 catalyzed by cytochrome P450 (CYP) requires 25-hydroxylation and subsequent 1α-hydroxylation to produce the hormonal activated 1α,25-dihydroxyvitamin D3. Vitamin D3 25-hydroxylase catalyses the first step in the vitamin D3 biosynthetic pathway, essential in the de novo activation of vitamin D3. A CYP known as CYP107CB2 has been identified as a novel vitamin D hydroxylase in Bacillus lehensis G1. In order to deepen the understanding of this bacterial origin CYP107CB2, its detailed biological functions as well as biochemical characteristics were defined. CYP107CB2 was characterized through the absorption spectral analysis and accordingly, the enzyme was assayed for vitamin D3 hydroxylation activity. CYP-ligand characterization and catalysis optimization were conducted to increase the turnover of hydroxylated products in an NADPH-regenerating system. Results revealed that the over-expressed CYP107CB2 protein was dominantly cytosolic and the purified fraction showed a protein band at approximately 62 kDa on SDS-PAGE, indicative of CYP107CB2. Spectral analysis indicated that CYP107CB2 protein was properly folded and it was in the active form to catalyze vitamin D3 reaction at C25. HPLC and MS analysis from a reconstituted enzymatic reaction confirmed the hydroxylated products were 25-hydroxyitamin D3 and 1α,25-dihydroxyvitamin D3 when the substrates vitamin D3 and 1α-hydroxyvitamin D3 were used. Biochemical characterization shows that CYP107CB2 performed hydroxylation activity at 25 °C in pH 8 and successfully increased the production of 1α,25-dihydroxyvitamin D3 up to four fold. These findings show that CYP107CB2 has a biologically relevant vitamin D3 25-hydroxylase activity and further suggest the contribution of CYP family to the metabolism of vitamin D3.
    Matched MeSH terms: Bacterial Proteins/genetics; Bacterial Proteins/metabolism; Bacterial Proteins/chemistry*; Recombinant Proteins/genetics; Recombinant Proteins/metabolism; Recombinant Proteins/chemistry
  18. Atomic models for the polypeptide backbones of myohemerythrin and hemerythrin
    Hendrickson WA, Ward KB
    Biochem Biophys Res Commun, 1975 Oct 27;66(4):1349-56.
    PMID: 5
    Matched MeSH terms: Muscle Proteins*
  19. Fulltext Effects of Modified Metakaolin Using Nano-Silica on the Mechanical Properties and Durability of Concrete
    Shafiq N, Kumar R, Zahid M, Tufail RF
    Materials (Basel), 2019 Jul 17;12(14).
    PMID: 31319615 DOI: 10.3390/ma12142291
    This paper discussed the effects of modified metakaolin (MK) with nano-silica (NS) on the mechanical properties and durability of concrete. In the first phase, trial mixes of concrete were prepared for achieving the desired value of the 28 days compressive strength, and the charge passed in rapid chloride permeability test (RCPT). In the second phase, statistical analysis was performed on the experimental results using the response surface method (RSM). The RSM was applied for optimizing the mix proportions for the required performance by exploiting the relationship between the mix characteristics and the corresponding test results. A blend of 10% MK + 1% NS as part of cement replacement exhibited the highest mechanical properties and durability characteristics of concrete; concrete mix showed that the 28-days compressive strength (CS) was 103 MPa, which was 15% greater than the CS of the control mix without MK or NS. The same mix showed more than 40% higher flexural and split-tensile strength than the control mix; also it resulted in a reduction of 73% in the rapid chloride permeability value. ANOVA technique was used for optimizing the nano-silica and metakaolin content for achieving maximum compressive strength and minimum RCPT value. Statistical analysis using ANOVA technique showed that the maximum compressive strength and lowest RCPT value could be achieved with a blend of 10% MK and 1.55% NS.
    Matched MeSH terms: Nerve Tissue Proteins; RNA-Binding Proteins
  20. Fulltext Serum from Nipah Virus Patients Recognises Recombinant Viral Proteins Produced in Escherichia coli
    Tiong V, Lam CW, Phoon WH, AbuBakar S, Chang LY
    Jpn J Infect Dis, 2017 Jan 24;70(1):26-31.
    PMID: 27169942 DOI: 10.7883/yoken.JJID.2015.501
    The genes for Nipah virus (NiV) proteins were amplified from viral RNA, cloned into the plasmid pTriEx-3 Hygro, expressed, and purified using immobilized metal affinity chromatography. The recombinant N, F, and G NiV proteins (rNiV-N, rNiV-F, and rNiV-G), were successfully expressed in Escherichia coli and purified with a yield of 4, 16, and 4 mg/L, respectively. All 3 recombinant viral proteins reacted with all 19 samples of NiV-positive human sera. The rNiV-N and rNiV-G proteins were the most immunogenic. The recombinant viral proteins did not react with any of the 12 NiV-negative sera. However, serum from a patient with a late-onset relapsing NiV infection complication was found to be primarily reactive to rNiV-G only. Additionally, there is a distinctive variation in the profile of antigen-reactive bands between the sample from a case of relapsing NiV encephalitis and that of acute NiV infection. The overall findings of this study suggest that the recombinant viral proteins have the potential to be developed further for use in the detection of NiV infection, and continuous biosurveillance of NiV infection in resource-limited settings.
    Matched MeSH terms: Recombinant Proteins/genetics; Recombinant Proteins/immunology*; Recombinant Proteins/isolation & purification; Viral Structural Proteins/genetics; Viral Structural Proteins/immunology*; Viral Structural Proteins/isolation & purification
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