HUMAN TUMOR CATHEPSIN-B - COMPARISON WITH NORMAL LIVER CATHEPSIN-B
HUMAN TUMOR CATHEPSIN-B - COMPARISON WITH NORMAL LIVER CATHEPSIN-B
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DOI：
10.1042/bj2850427
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发表时间：
1992-07-15
影响因子：
4.1
通讯作者：
SLOANE, BF
中科院分区：
文献类型：
--
作者：
MOIN, K;DAY, NA;SLOANE, BF
组织蛋白酶B从正常人肝和几种人肿瘤组织中纯化并部分表征。 在SDS/聚丙烯酰胺凝胶中检测到三种形式的组织蛋白酶B，分子量为25 kDa，26 kDa（两种呈现为双峰）和30 kDa。 25-26 kDa的双联体与来自肿瘤和正常肝脏的含有最高组织蛋白酶B活性的组分相关。 两种来源的组织蛋白酶B显示出相似的最适pH。 正常肝脏和肿瘤组织蛋白酶B对选定的合成底物表现出相似的动力学。 在中性pH和24 ℃下，正常肝脏和肿瘤组织蛋白酶B均表现出较低的K（m）和较高的k（cat.）/ K（m）比在pH 6.0。 它们对合成抑制剂的抑制谱也相似。 用抗成熟双链形式的人肝组织蛋白酶B的单特异性抗体和抗组织蛋白酶B衍生的合成肽的抗体进行的免疫学研究确立了肝酶和肿瘤酶的免疫学相似性。 25 kDa和26 kDa形式的N-末端序列与人组织蛋白酶B的成熟双链形式的重链的N-末端序列相同，而30 kDa种类的N-末端序列与人组织蛋白酶B的单链形式的N-末端序列相同。 用内切糖苷酶肽-N4-（N-乙酰基-β-葡糖胺）天冬酰胺酰胺酶处理来自正常肝脏和肿瘤的双链形式的组织蛋白酶B，在SDS/聚丙烯酰胺凝胶中将26 kDa形式转化为25 kDa，表明组织蛋白酶B可能以糖基化和非糖基化形式存在。 我们的研究结果，在与小鼠组织蛋白酶B的早期报道相比，表明人类肝脏和肿瘤组织蛋白酶B是相似的。
Cathepsin B was purified from normal human liver and several human tumour tissues and partially characterized. Three forms of cathepsin B, with molecular masses of 25 kDa, 26 kDa (the two appearing as a doublet) and 30 kDa, were detected in SDS/polyacrylamide gels. The 25-26 kDa doublet was associated with the fractions from tumours and normal liver containing the highest cathepsin B activity. Cathepsin B from both sources showed similar pH optima. Both normal liver and tumour cathepsin B exhibited similar kinetics against selected synthetic substrates. At neutral pH and 24-degrees-C, cathepsin B from both normal liver and tumour exhibited a lower K(m) and a higher k(cat.)/K(m) than at pH 6.0. Their inhibitory profiles against synthetic inhibitors were also similar. Immunological studies with a monospecific antibody against the mature double-chain form of human liver cathepsin B and an antibody against a cathepsin B-derived synthetic peptide established the immunological similarity of liver and tumour enzymes. The N-terminal sequences of the 25 kDa and 26 kDa forms were identical with that of the heavy chain of the mature double-chain form of human cathepsin B, whereas the N-terminal sequence of the 30 kDa species was identical with that of the single-chain form of human cathepsin B. Treatment of the double-chain form of cathepsin B from normal liver and tumours with the endoglycosidase peptide-N4-(N-acetyl-beta-glucosaminyl)asparagine amidase converted the 26 kDa form into 25 kDa in SDS/polyacrylamide gels, suggesting that cathepsin B may exist as both glycosylated and unglycosylated forms. Our results, in contrast with those reported earlier for mouse cathepsin B, indicate that human liver and tumour cathepsin B are similar.