PURIFICATION OF THE MAIN SOMATOSTATIN-DEGRADING PROTEASES FROM RAT AND PIG BRAINS, THEIR ACTION ON OTHER NEUROPEPTIDES, AND THEIR IDENTIFICATION AS ENDOPEPTIDASES 24.15 AND 24.16
PURIFICATION OF THE MAIN SOMATOSTATIN-DEGRADING PROTEASES FROM RAT AND PIG BRAINS, THEIR ACTION ON OTHER NEUROPEPTIDES, AND THEIR IDENTIFICATION AS ENDOPEPTIDASES 24.15 AND 24.16
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DOI：
10.1111/j.1432-1033.1992.tb17168.x
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发表时间：
1992-08-15
期刊：
影响因子：
--
通讯作者：
MENTLEIN, R
中科院分区：
文献类型：
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作者：
DAHMS, P;MENTLEIN, R
从大鼠和猪脑匀浆中纯化了主要的生长抑素降解蛋白酶，其特征在于硫醇和金属依赖性内切蛋白酶。两种类型的蛋白酶与表观天然和亚基分子量为70 kDa和68 kDa的，可以区分在这两个物种。除了生长抑素，都水解其他几个神经肽的链长在8和30个氨基酸残基之间。切割位点通常相似或相同，但对于来自两种物种的酶观察到一些明显的例外，其可用于区分两种蛋白酶。68-kDa蛋白酶在三个键处切割生长抑素（Asn 5-Phe 6、Phe 6-Phe 7和Thr 10-Phe 11）和仅在Arg 8-Arg 9键处的神经降压素，而70-kDa蛋白酶仅在两个键处消化生长抑素（Phe 6-Phe 7和Thr 10-Phe 11）和神经降压素以及乙酰神经降压素-（8-13）（猪蛋白酶）或几乎完全（大鼠蛋白酶）在Pro 10-Tyr 11键处。然而，各种肽的相对速率的digestion，更依赖于物种比蛋白酶的类型。切割位点血管紧张素II，缓激肽，强啡肽，促性腺激素释放素和P物质，除了不同的利率，相同的两种蛋白酶。在这两个物种的68-kDa蛋白酶被认为是主要的，但不是唯一的，可溶性的，而不是膜相关的，而相反的70-kDa蛋白酶检测。基于不同的分子和催化性质，68-kDa蛋白酶应该与内肽酶24.15（EC 3.4.24.15）、70-kDa蛋白酶与内肽酶24.16（EC 3.4.24.16，神经降压素降解内肽酶）一致。这项调查表明，这两种蛋白酶水解各种神经肽具有相似的切割位点，但具有物种依赖性的活动。物种独立的区别是内肽酶24.16对乙酰神经降压素-（8 - 13）的排他性作用和仅由内肽酶24.15从生长抑素释放游离苯丙氨酸。
The main somatostatin-degrading proteases were purified from rat and pig brain homogenates and characterized as thiol- and metal-dependent endoproteases. Two types of proteases with apparent native and subunit molecular masses of 70 kDa and 68 kDa could be differentiated in both species. Beside somatostatin, both hydrolyzed several other neuropeptides with chain lengths between 8 and 30 amino acid residues. Cleavage sites were generally similar or identical, but some clear exceptions were observed for enzymes from both species which could be used to differentiate between the two proteases. The 68-kDa protease cleaved somatostatin at three bonds (Asn5-Phe6, Phe6-Phe7 and Thr10-Phe11) and neurotensin only at the Arg8-Arg9 bond, whereas the 70-kDa protease digested somatostatin at only two bonds (Phe6-Phe7 and Thr10-Phe11) and neurotensin as well as acetylneurotensin-(8-13) additionally (pig protease) or almost exclusively (rat protease)at the Pro10-Tyr11 bond. Relative rates for the digestions of various peptides were, however, more dependent on the species than on the type of protease. Cleavage sites for angiotensin II, bradykinin, dynorphin, gonadoliberin and substance P were, apart from different rates, identical for both proteases. In both species the 68-kDa protease was found to be mainly, but not exclusively, soluble and not membrane-associated, whereas the inverse was detected for the 70-kDa protease. Based on distinct molecular and catalytic properties, the 68-kDa protease is supposed to be congruent with the endopeptidase 24.15 (EC 3.4.24.15), the 70-kDa protease with endopeptidase 24.16 (EC 3.4.24.16, neurotensin-degrading endopeptidase). This investigation demonstrates that both proteases hydrolyze various neuropeptides with similar cleavage sites, but with species-dependent activity. Species-independent distinctions are the exclusive action of endopeptidase 24.16 on acetylneurotensin-(8 - 13) and liberation of free Phe from somatostatin only by endopeptidase 24.15.