Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Type III procollagen was isolated from the serum-free culture media of human foreskin fibroblasts by adsorption to controlled-pore glass beads and chromatography of the eluted procollagen pool on diethylaminoethylcellulose [Gerard, S., & Mitchell, W. M. (1979) Anal. Biochem. 96, 433-447]. Sodium dodecyl sulfate (NaDodSO4) electrophoresis in 1% agarose-2% acrylamide gels with or without prior sample reduction revealed the predominance of a band with retarded mobility as compared to human procollagen I [hupro(I)]. Digestion of hupro(III) with pepsin yielded a product whose electrophoretic mobility was retarded for both the intact trimer and its reduced monomeric subunit as compared to that for the respective bands of rat skin (type I) collagen. NaDodSO4-polyacrylamide gel electrophoresis of bacterial collagenase-digested hupro(III) demonstrated disulfide-bonded propeptides which upon reduction were replaced by two distinct monomeric propeptide bands. The amino acid composition of hupro(III) was similar to that of hupro(I) but contained increased amounts of HO-Pro and Cys and less Thr, Ala, Val, and Arg. Sedimentation equilibrium analysis in 1 M CaCl2 yielded at extrapolated zero concentration a Mr of 505 +/- 25K. A [hupro(III) - collagen(III)] circular dichroic difference spectrum suggests approximately 10% alpha helix. The zero-order mutarotation rate of hupro(III) (vo = 55.0 X 10(-5) s-1) was twice that of hucol(III) (vo = 25.4 X 10(-5) s-1) at 20 degrees C, which may reflect the influence of the interchain disulfide-bonded carboxyl propeptides on the process of collagen fold formation.
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PMID:Physical and chemical properties of human type III procollagen. 683 54

We have used the human promonocyte-like U937 cell line as a model to study the regulation of interstitial collagenase and tissue inhibitor of metalloproteinases (TIMP) during mononuclear phagocyte development. Our results show that differentiation of U937 cells with exposure to 12-O-tetradecanoylphorbol 13-acetate (TPA) induces a temporally delayed (16-24 h) but marked increase in the biosynthesis and secretion of interstitial collagenase and TIMP. Similarly, steady-state mRNA levels for both proteins rose dramatically during the period of exposure, but again after considerable time delay (12-16 h). For interstitial collagenase, induction was transcriptionally regulated as demonstrated by nuclear run-on experiments, and required the synthesis of proteins as indicated by cycloheximide treatment. However, transcriptional activation of collagenase was never observed prior to 10-12 h; since c-fos is rapidly induced in U937 cells and largely disappears by 2 h (Mitchell et al., 1985), our data strongly suggest that collagenase induction in this system cannot be explained simply or entirely by an AP-1-dependent mechanism. Although TIMP steady-state mRNA levels also increased substantially with cellular differentiation, no transcription was detected by run-on experiments. However, TPA exposure markedly prolonged the half-life of TIMP mRNA from 4 h to > 20 h. While cycloheximide treatment completely blocked TPA-mediated induction of collagenase mRNA, it only marginally interfered with simultaneously induced TIMP mRNA levels. Our results demonstrate that differentiation of U937 monocytic cells is accompanied by markedly enhanced production of both interstitial collagenase and TIMP. However, there are multiple, and perhaps differing, molecular mechanisms regulating these responses.
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PMID:Molecular mechanisms regulating the production of collagenase and TIMP in U937 cells: evidence for involvement of delayed transcriptional activation and enhanced mRNA stability. 847 58