Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.23.5 (cathepsin D)
 4,130 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two acid proteases, one hydrolysing hemoglobin and the other hydrolysing benzoyl arginine naphthyamide (BANA), were separated and partially purified from human skin buffer extract. The acid protease hydrolysing hemoglobin was purified about 190 fold by Sephadex G-100 gel filtration and DEAE-cellulose chromatography. It hydrolysed hemoglobin at pH 3.5, casein at pH 5.8 and skin protein substrate at pH 6.0. It did not markedly hydrolyse synthetic protease substrates. The molecular size of this protease was 38000. The protease was insensitive to common protease modifiers and closely resembles cathepsin D purified from other organs. The BANA-hydrolysing acid protease was purified about 760 fold by Sephadex G-100 gel filtration and affinity chromatography on organomercurial Sepharose 4B gel. It preferentially hydrolysed BAEE, BANA and BAA with an optimum at pH 5.8. The hydrolysis of BAPA, LeuNA and protein substrates was very low. This acid protease was found to be highly dependent on reducing agents, as DTT, and chelating agents, as EDTA, and was inhibited by pCMB and TLCK. The molecular size of the enzyme was 28000. This protease closely resembles cathepsin B1 purified from other organs. Human skin was also shown to contain a low activity of benzoyl arginine amide (BAA) hydrolysing acid protease with a molecular size of about 50000 and resembling cathepsin B2. Human skin contained an inhibitor with a molecular size of about 13000 against human skin cathepsin B1. This inhibitor did not inhibit trypsin, chymotrypsin or skin proteases other than cathepsin B1.
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PMID:Human skin proteases. Separation and characterization of two acid proteases resembling cathepsin B1 and cathepsin D and of an inhibitor of cathepsin B1. 0 17

S-S cross-linking enzyme, skin sulfhydryl oxidase (SSO), catalyzes the formation of disulfide bonds from sulfhydryl groups in skin. The activity of SSO was detected in differing amounts in each of the four layers--stratum corneum, stratum granulosum, stratum spinosum with basal cell layer, and dermis--of cow snout skin, with the highest specific activity being recorded in the stratum granulosum. SSO was stimulated to 130-150% of its initial activity by treatment with 1 mg/ml trypsin, chymotrypsin, or urokinase, but was not affected by plasmin or cathepsin D. These findings suggest that SSO may be activated by some kinds of serine proteases during the keratinocyte autolysis process in the stratum granulosum. SSO showed the highest activity with the addition of 5 microM of Cu2+. The atomic absorptive analysis of purified SSO showed 0.5 atoms of Cu in one molecule of SSO. From these findings, it was determined that Cu2+ was essential for the activity of SSO. The molar ratio of the disappearance of DTT, consumption of O2, and production of H2O2 during the enzyme reaction was 1:1.05:0.89. From these findings, the reactions catalyzed by SSO is suggested to be represented by the following equation: (table; see text).
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PMID:[Localization in skin, activation and reaction mechanisms of skin sulfhydryl oxidase]. 258 80

Lysosomal cysteine proteinases were fractionated from partially purified rat muscle lysosomes. By gel filtration on Sephadex G75, cathepsin D was separated from two thiol-requiring proteolytic fractions of Mr 25 000 and 55 000, respectively. By chromatofocusing, the first fraction (Mr = 25 000) was resolved into three isoenzymic forms of cathepsin H, eluted at pH 5.8, 6.0 and 7.2, respectively, and two isoenzymic forms of cathepsin B, eluted at pH 5.5 and 5.25. Cathepsin H isoenzymes hydrolyzed Arg-NNap and BANA, were totally inhibited by 1 mM p-CMB and only to 60% by 5.10(-5) M leupeptin. The two forms of cathepsin B which degraded Z-Phe-Arg-NMec, Z-Arg-Arg-NNap and BANA were very sensitive to p-CMB and leupeptin. In addition to cathepsins B and H, a typical cathepsin-L- like activity was found in this fraction but only as a very minor component. The high Mr fraction (Mr = 55 000) contained a cysteine proteinase hydrolyzing, at pH 6.0, Z-Phe-Arg-NMec, and to a lesser extent Z-Arg-Arg-NNap and BANA. Unlike cathepsins B and H, it was very sensitive to p-CMB and HgCl2 and was fully activated only in the presence of 10 mM DTT, and inhibited to 93% by 2.10(-8) M leupeptin. By chromatofocusing, it was resolved into several isoenzymatic forms, eluted between pH 5.8 and 4.0.
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PMID:Cysteine proteinase content of rat muscle lysosomes. Evidence for an unusual proteinase activity. 639