Fructose-1,6-bisphosphate aldolase (FbA), a well characterized glycometabolism enzyme, has been found to participate in other important processes besides the classic catalysis. To understand the important functions of three fructose-1,6-bisphosphate aldolases from Clonorchis sinensis (CsFbAs, CsFbA-1/2/3) in host-parasite interplay, the open reading frames of CsFbAs were cloned into pET30a (+) vector and the resulting recombinant plasmids were transformed into Escherichia coli BL21 (DE3) for expression of the proteins. Purified recombinant CsFbAs proteins (rCsFbAs) were approximately 45.0 kDa on 12% SDS-PAGE and could be probed with each rat anti-rCsFbAs sera by western blotting analysis. ELISA and ligand blot overlay indicated that rCsFbAs of 45.0 kDa as well as native CsFbAs of 39.5 kDa from total worm extracts and excretory-secretory products of Clonorchis sinensis (CsESPs) could bind to human plasminogen, and the binding could be efficiently inhibited by lysine analog ε-aminocaproic acid. Our results suggested that as both the components of CsESPs and the plasminogen binding proteins, three CsFbAs might be involved in preventing the formation of the blood clot so that Clonorchis sinensis could acquire enough nutrients from host tissue for their successful survival and colonization in the host. Our work will provide us with new information about the biological function of three CsFbAs and their roles in hostparasite interplay.
Helicobacter pylori infection results in diverse clinical conditions ranging from chronic gastritis and ulceration to gastric adenocarcinoma. Among the multiethnic population of Malaysia, Indians consistently have a higher H. pylori prevalence as compared with Chinese and Malays. Despite the high prevalence of H. pylori, Indians have a relatively low incidence of peptic ulcer disease and gastric cancer. In contrast, gastric cancer and peptic ulcer disease incidence is high in Chinese. H. pylori strains from Chinese strains predominantly belong to the hspEAsia subpopulation while Indian/Malay strains mainly belong to the hspIndia subpopulation. By comparing the genome of 27 Asian strains from different subpopulations, we identified six genes associated with risk of H. pylori-induced peptic ulcer disease and gastric cancer. This study serves as an important foundation for future studies aiming to understand the role of bacterial factors in H. pylori-induced gastro-duodenal diseases.
Plasmodium knowlesi can cause severe and fatal human malaria in Southeast Asia. Rapid diagnosis of all Plasmodium species is essential for initiation of effective treatment. Rapid diagnostic tests (RDTs) are sensitive for detection of uncomplicated and severe falciparum malaria but have not been systematically evaluated in knowlesi malaria. At a tertiary referral hospital in Sabah, Malaysia, we prospectively evaluated the sensitivity of two combination RDTs for the diagnosis of uncomplicated and severe malaria from all three potentially fatal Plasmodium species, using a pan-Plasmodium lactate dehydrogenase (pLDH)-P. falciparum histidine-rich protein 2 (PfHRP2) RDT (First Response) and a pan-Plasmodium aldolase-PfHRP2 RDT (ParaHIT). Among 293 hospitalized adults with PCR-confirmed Plasmodium monoinfection, the sensitivity of the pLDH component of the pLDH-PfHRP2 RDT was 74% (95/129; 95% confidence interval [CI], 65 to 80%), 91% (110/121; 95% CI, 84 to 95%), and 95% (41/43; 95% CI, 85 to 99%) for PCR-confirmed P. knowlesi, P. falciparum, and P. vivax infections, respectively, and 88% (30/34; 95% CI, 73 to 95%), 90% (38/42; 95% CI, 78 to 96%), and 100% (12/12; 95% CI, 76 to 100%) among patients tested before antimalarial treatment was begun. Sensitivity in severe malaria was 95% (36/38; 95% CI, 83 to 99), 100% (13/13; 95% CI, 77 to 100), and 100% (7/7; 95% CI, 65 to 100%), respectively. The aldolase component of the aldolase-PfHRP2 RDT performed poorly in all Plasmodium species. The pLDH-based RDT was highly sensitive for the diagnosis of severe malaria from all species; however, neither the pLDH- nor aldolase-based RDT demonstrated sufficiently high overall sensitivity for P. knowlesi. More sensitive RDTs are needed in regions of P. knowlesi endemicity.
We determined the differential expression levels of proteins in peripheral blood mononuclear cells of patients with dengue fever (DF) and dengue hemorrhagic fever (DHF). Proteins were subjected to two-dimensional electrophoresis, mass spectrometry and Western blot analysis. We identified 8 proteins that were 2-fold or more up-regulated in patients compared to healthy control, three of which, aldolase, thioredoxin peroxidase and alpha tubulin, were related to dengue infection. Both thioredoxin peroxidase and alpha tubulin were over-expressed 4.9 and 3.3 times respectively in DHF compared to DF patients while aldolase was up-regulated 2.2 times in DF compared to DHF patients. Alpha tubulin and thioredoxin peroxidase have the potential to be utilized as biomarkers for DHF.
The fructose-1,6-bisphosphate aldolase catalyzed glycolysis branch that forms dihydroxyacetone phosphate and glyceraldehyde-3-phosphate was identified as a key driver of increased oil synthesis in oil palm and was validated in Saccharomyces cerevisiae. Reduction in triose phosphate isomerase (TPI) activity in a yeast knockdown mutant resulted in 19% increase in lipid content, while yeast strains overexpressing oil palm fructose-1,6-bisphosphate aldolase (EgFBA) and glycerol-3-phosphate dehydrogenase (EgG3PDH) showed increased lipid content by 16% and 21%, respectively. Genetic association analysis on oil palm SNPs of EgTPI SD_SNP_000035801 and EgGAPDH SD_SNP_000041011 showed that palms harboring homozygous GG in EgTPI and heterozygous AG in EgGAPDH exhibited higher mesocarp oil content based on dry weight. In addition, AG genotype of the SNP of EgG3PDH SD_SNP_000008411 was associated with higher mean mesocarp oil content, whereas GG genotype of the EgFBA SNP SD_SNP_000007765 was favourable. Additive effects were observed with a combination of favourable alleles in TPI and FBA in Nigerian x AVROS population (family F7) with highest allele frequency GG.GG being associated with a mean increase of 3.77% (p value = 2.3E-16) oil content over the Family 1. An analogous effect was observed in yeast, where overexpressed EgFBA in TPI - resulted in a 30% oil increment. These results provide insights into flux balances in glycolysis leading to higher yield in mesocarp oil-producing fruit.