蛋白水解和non-proteolytic激活人类嗜中性粒细胞progelatinase B。
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唱QX,他Birkedal-Hansen H, Van疣
蛋白水解和non-proteolytic激活人类嗜中性粒细胞progelatinase B。
Biochim Biophys学报。1995年9月6日,1251 (2):99 - 108。
- PubMed ID
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7669817 (在PubMed]
- 文摘
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人类嗜中性粒细胞的激活progelatinase B (pro-HNG)由多种蛋白水解和non-proteolytic催化剂已被调查。激活效率的定量比较治疗之前报道激活pro-HNG或其他细胞产生的相关白明胶酶B物种表明stromelysin和胰蛋白酶是良好的催化剂。HgCl2适度有效的催化剂,而p-chloromercuribenzoate和NaOCl可怜的活化剂。它也表明,人类matrilysin和fibroblast-type胶原酶可以通过一种机制,激活pro-HNG stromelysin非常相似。最初,这些蛋白酶水解Glu40-Met41债券88 kDa前肽域生成一个不活跃的HNG物种。胶原酶也生成一个68 kDa HNG物种通过水解Ala74-Met75债券。最终,要么matrilysin治疗,胶原酶和胰蛋白酶的结果在生产65 kDa的活跃的HNG形式,起源于Arg87-Phe88键的水解。这是相同的活性物种产生stromelysin激活。这个裂解位点下游cysteine-switch的残渣位于80和释放位置,占的永久激活酶。这些结果表明,matrilysin和胶原酶可能是生理pro-HNG有关催化剂和/或其他progelatinase B的物种。 Activation by HgCl2 produces an active 68 kDa enzyme due to autolytic hydrolysis of the Ala74-Met75 bond. This species retains the cysteine switch residue; however, it is shown that it is only active in the continued presence of HgCl2. Removal of the HgCl2 restores latency, indicating that this species is reversibly activated by HgCl2, which functions by complexing the sulfhydryl group of the cysteine switch residue and keeping it dissociated from the active site zinc atom. Thus, in spite of reports to the contrary, the cysteine switch mechanism can account for the latency and activation of pro-HNG.