Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There is a marked increase in the half-cystine content of bacterial spores, especially the coat layers at the time of formation of the outer coat. When a cysteine auxotroph of Bacillus cereus T is grown on limiting cysteine, the spores contain the normal content of half-cystine, suggesting an alternate source. Glutathione appears to be such a supply of cysteine since it is hydrolyzed during sporulation and there are increased activities of the hydrolyzing enzymes at the same time. In addition, a cysteine auxotroph with a second alteration, a temperature-sensitive glutathione disulfide reductase, produces lysozyme-sensitive spores at 40 C. These spores appear to be defective in the formation of outer spore coat. During sporulation at 40 C, the double mutant accumulates oxidized glutathione which is a poor substrate for the hydrolytic enzymes. As a result, sporulating cells are deficient in half-cystines which are essential for outer spore coat morphogenesis. This alteration can be overcome by a shift to 30 C or by addition of cystinyl-pencillamine or cysteinyl-glycine to cultures sporulating at 40 C.
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PMID:Role of glutathione in the morphogenesis of the bacterial spore coat. 463 93

In mammalian spermiogenesis, sperm mature during epididymal transit to get fertility. The pig sharing many physiological similarities with humans is considered a promising animal model in medicine. We examined the expression profiles of proteins from boar epididymal caput, corpus, and cauda sperm by two-dimensional gel electrophoresis and peptide mass fingerprinting. Our results indicated that protein disulfide isomerase-P5 (PDI-P5) human homolog was down-regulated from the epididymal corpus to cauda sperm, in contrast to the constant expression of protein disulfide isomerase A3 (PDIA3) human homolog. To examine the functions of PDIA3 and PDI-P5, we cloned and sequenced cDNAs of pig PDIA3 and PDI-P5 protein precursors. Each recombinant pig mature PDIA3 and PDI-P5 expressed in Escherichia coli showed thiol-dependent disulfide reductase activities in insulin turbidity assay. Although PDIA3 showed chaperone activity to promote oxidative refolding of reduced denatured lysozyme, PDI-P5 exhibited anti-chaperone activity to inhibit oxidative refolding of lysozyme at an equimolar ratio. SDS-PAGE and Western blotting analysis suggested that disulfide cross-linked and non-productively folded lysozyme was responsible for the anti-chaperone activity of PDI-P5. These results provide a molecular basis and insights into the physiological roles of PDIA3 and PDI-P5 in sperm maturation and fertilization.
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PMID:Protein disulfide isomerase-P5, down-regulated in the final stage of boar epididymal sperm maturation, catalyzes disulfide formation to inhibit protein function in oxidative refolding of reduced denatured lysozyme. 2015 40