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)

A micromethod is described for the production of lysed preparations of Thiobacillus A2 following treatment with lysozyme and EDTA. These may be used for the assay of intra-cellular enzymes including rhodanese, hexokinase, glucose 6-phosphate dehydrogenase and phosphoglucoseisomerase. The procedure is useful for assaying enzymes in samples too small to be treated by conventional mechanical methods, but gives comparable recoveries of enzyme activities.
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PMID:An enzymatic lysis procedure for the assay of enzymes in Thiobacillus A2. 664 82

The 29-kDa FK506 binding protein (FKBP) gene is the only peptidyl-prolyl cis-trans isomerase (PPIase) gene in the genome of Pyrococcus horikoshii. We characterized the function of this FKBP (PhFKBP29) and used it to increase the production yield of soluble recombinant protein in Escherichia coli. The PPIase activity (k(cat)/K(m)) of PhFKBP29 was found to be much lower than that of other archaeal 16- to 18-kDa FKBPs by a chymotrypsin-coupled assay of the oligo-peptidyl substrate at 15 degrees C. Besides this low PPIase activity, PhFKBP29 showed chaperone-like protein folding activity which enhanced the refolding yield of chemically unfolded rhodanese in vitro. In addition, it suppressed thermal protein aggregation in a temperature range of 45 to 100 degrees C. When the PhFKBP29 gene was coexpressed with the recombinant Fab fragment gene of the anti-hen egg lysozyme antibody in the cytoplasm of E. coli, whose expressed product tended to form an inactive aggregate in E. coli, it improved the yield of the soluble Fab fragments with antibody specificity. PhFKBP29 exerted protein folding and aggregation suppression in E. coli cells.
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PMID:FK506 binding protein from the hyperthermophilic archaeon Pyrococcus horikoshii suppresses the aggregation of proteins in Escherichia coli. 1182 79

Aggregation of alpha-synuclein is thought to play a major role in the pathogenesis of Parkinson's disease (PD), which is characterized by the presence of intracytoplasmic Lewy bodies (LB) in the brain. alpha-Synuclein and its deletion mutants are largely unfolded proteins with random coil structures as revealed by CD spectra, fluorescence spectra, gel filtration chromatography, and ultracentrifugation. On the basis of its highly unfolded and flexible conformation, we have investigated the chaperone-like activity of alpha-synuclein in vitro. In our experiments, alpha-synuclein inhibited the aggregation of model substrates and protected the catalytic activity of alcohol dehydrogenase and rhodanese during heat stress. In addition, alpha-synuclein inhibited the initial aggregation of reduced/denatured lysozyme on the refolding pathway. Interestingly, deletion of the C-terminal regions led to the abolishment of chaperone activity, although largely unstructured conformations are maintained. Moreover, alpha-synuclein could inhibit the aggregation of various Escherichia coli cellular proteins during heat stress, and C-terminal deletion mutants could not provide any protection to these cellular proteins. Results with synthetic C-terminal peptides and C-terminal deletion mutants suggest that the second acidic repeat, (125)YEMPSEEGYQDYEPEA(140), is important for the chaperone activity of alpha-synuclein, and C-terminal deletion leads to the facilitated aggregation with the elimination of chaperone activity.
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PMID:Structural and functional implications of C-terminal regions of alpha-synuclein. 1242 41

The Escherichia coli expression system remains the first choice for the production of recombinant proteins when biological activity is not compromised by posttranslational modification. Many strains of E. coli, vectors and culture conditions are available to express recombinant proteins in a soluble and correctly folded conformation. Often these strategies fail, and misfolded recombinant proteins aggregate into inclusion bodies. To recover its biological activity, a recombinant protein must be refolded, a step that has become the major limitation of the E. coli expression system. Chromatographic refolding, assisted by immobilized chaperones and foldases, is an in vitro refolding protocol that significantly improves refolding yields, yet its application at the bioprocess scale has been limited. Therefore, new cost-efficient alternatives to utilize chromatographic refolding assisted by chaperones and foldases might improve the production of biologically active proteins in E. coli. In this work, the GroEL apical domain (AD) and the oxidoreductases DsbA and DsbC fused to a carbohydrate-binding module (CBM) were purified and immobilized on microcrystalline cellulose particles. A column packed with a 60:40 (v/v) mixture of gel filtration media and cellulose particles with immobilized AD significantly improved the chromatographic refolding of rhodanese. A similar column with equimolar amounts of AD, DsbA and DsbC immobilized on cellulose particles significantly improved the oxidative chromatographic refolding of lysozyme. The assisted refolding yields were up to 80% for rhodanese and 100% for lysozyme, compared with 33% and 23%, respectively, obtained in the experiments without immobilized chaperones. In addition, AD, DsbA and DsbC immobilized on cellulose exhibited significant operational stability under the extreme denaturing conditions used in the chromatographic refolding batches. These results suggest that chromatographic refolding assisted by AD, DsbA, and DsbC immobilized on cellulose is suitable for the oxidative refolding of proteins expressed in E. coli as inclusion bodies.
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PMID:Chromatographic refolding of rhodanese and lysozyme assisted by the GroEL apical domain, DsbA and DsbC immobilized on cellulose. 2270 67