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

Glomerular IgA deposits were eluted from biopsied kidney tissues of patients with IgA nephritis and the antibody specificity was analyzed. The IgA was successfully eluted with combined use of citrate buffer and collagenase. The elution procedure did not attenuate antibody activity which was confirmed by the preliminary experiment that mouse IgA monoclonal anti-DNP antibody similarly treated did not cause any decline of antigen-binding ability. Because of the limited amounts ranging from 80-800 ng/ml, the eluted IgA did not react with respective lysates of the kidney tissues from which the IgA had derived. Moreover, kidney tissues from 9 biopsies yielded 5 micrograms/ml of IgA, when mixed together as source of IgA; nevertheless, the eluted IgA did not react with the kidney lysates, either. The eluted IgA, however, did react with several bacterial antigens, among which the 34-kDa antigen from Haemophilus influenzae (34-kDa H. influenzae) was most clearly detected with IgA eluted from pooled 10 kidney samples of IgA nephritis, which was confirming by Western blot analysis. The reactivity of the eluted IgA with the 34-kDa H. influenzae antigen was seen in 3/5 of IgA nephritis and 3/9 of non IgA nephritis patients with glomerular IgA deposits, respectively. The reactivity of serum IgA with the bacterial antigen was also investigated, which revealed that the serum IgA reacted with the 34-kDa antigen in 2/12 of IgA nephritis, 4/10 of liver cirrhosis patients and 3/10 of healthy control individuals, respectively. The surerum IgA from the IgA nephritis patients appeared to react with 34-kDa antigen more intensively than did healthy control IgAs. These results suggest that the 34-kDa H. influenzae plays an important role in the pathogenesis of at least certain IgA nephritis cases.
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PMID:[Isolation of glomerular IgA deposits from biopsied kidney tissues of patients with IgA nephritis and analysis of the antibody specificity of IgA]. 1042 65

Plasmin, the enzymatically active form of plasminogen, can activate several matrix metalloproteinases (MMPs). In this study, we investigated the activation of MMP-1, one of the major interstitial collagenases, by plasmin which was generated on the surface of Staphylococcus aureus cells. Plasmin bound to plasminogen receptors on S. aureus degraded the major (125)I-labeled 55-kDa proMMP-1 into the 42-kDa form corresponding to the size of active MMP-1. MMP-1 formed by S. aureus-bound plasmin was also enzymatically active as judged by digestion of the synthetic collagenase substrate, DNP-Pro-Leu-Gly-Leu-Trp-Ala-D-Arg-NH(2). The finding that, in MMP-1 molecules generated either by soluble plasmin or by S. aureus-bound plasmin, the amino-terminal amino acid sequences were identical indicated that the activation mechanisms of the two plasmin forms do not differ from each other. The present observations emphasise and broaden the physiological importance of bacterial plasminogen receptors. In addition to direct proteolytic effects on components of the extracellular matrix, receptor-bound plasmin is also capable of initiating an MMP-1-dependent matrix-degrading enzymatic cascade.
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PMID:Activation of interstitial collagenase, MMP-1, by Staphylococcus aureus cells having surface-bound plasmin: a novel role of plasminogen receptors of bacteria. 1056 88

MMPs, part of a family of enzymes with >35 known members, play an important role in tissue remodeling and repair, in the biology of neoplasia, and during development. Hydroxamic and carboxylic acid inhibitors of these proteases have long been available, but their specificities are poor and there still exists a desire to find novel chemical structures, which could be modified to optimize specificity and biocompatibility. Established methods for measuring MMP activity are based on the cleavage of MCA-PLGL-A2pr(DNP)-AR, which provides a prompt fluorescent signal when cleaved; however, its absorption/emission properties (325/400 nm) are not best suited for HTS assays. We describe an HTS-compatible method using the peptide substrate PLGLAARK, labeled at N- and C-termini with CyDye fluors Cy3 and Cy5Q, respectively, which is cleavable by MMP-1, -2, -3, -7, -9, and -13. HTS assays for MMP-13 and MMP-9 inhibitors were set up in approximately 20 microl in 384-well plates as a prompt fluorescence readout (excitation/emission = 540/570 nm) using the LEADseeker homogenous imaging system. These assays yielded IC(50) values comparable to standard methods, but with a faster, very sensitive, and normalized readout, thus conserving compound, enzyme (approximately 1.5 ng/well), and time (20 s read/plate). Data quality (Z' approximately 0.9) was such that hit-picking to -25% change in primary screening could be performed with confidence, and the subsequent rate of confirmation and validation in IC(50) determinations of the picked compounds was >60%. Parallel screening of related proteases also permitted immediate specificity comparisons, including evaluation of inactive or weakly active compounds.
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PMID:Development of an assay suitable for high-throughput screening to measure matrix metalloprotease activity. 1509 Jan 79

Polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs have been identified widely in occupational and environmental pollution, such as diesel engine emissions and other combustion products. In most cases, hepatic biotransformation is involved in converting these chemicals to their carcinogenic metabolites. It has been demonstrated that isolated hepatocytes possess substantial amounts of the enzymes responsible for metabolizing xenobiotics and are therefore a convenient model for studying chemicals that require activation to exert their carcinogenic effects. In this study, rat hepatocytes were isolated by collagenase digestion and then exposed to benzo[a]pyrene (B) [a]P), benzo[a]anthracene (B[a]A), 1-nitropyrene (1-NP) and 1,6-dinitropyrene (1,6-DNP) at different doses and/or times so that DNA adducts levels, as measured with the (32)P-postlabelling technique, could be compared. Each of the four compounds tested induced significant increases of total DNA adducts with clear dose-related responses. One or more individual adducts were identified as major adducts for each compound. Time-related increases of DNA adducts were also observed from 1 to 4 hr of incubation. Greater amounts of DNA adducts were induced by B[a]P or 1,6-DNP than by B[a]A or 1-NP, with potency being in the order 1,6-DNP > B[a]P > 1-NP B[a]A. These results demonstrate that freshly isolated hepatocytes can be used as an effective in vitro system for the detection of DNA adducts using (32)P-postlabelling, and have shown 1,6-DNP to be the most potent of the tested constituents of diesel emissions.
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PMID:Comparison of DNA adduct induction in vitro by PAHs and nitro-pahs in freshly isolated rat hepatocytes. 2065 Feb 52


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