INHIBITION OF RABBIT BRAIN PROLYL ENDOPEPTIDASE BY N-BENZYLOXYCARBONYL-PROLYL-PROLINAL, A TRANSITION-STATE ALDEHYDE INHIBITOR
INHIBITION OF RABBIT BRAIN PROLYL ENDOPEPTIDASE BY N-BENZYLOXYCARBONYL-PROLYL-PROLINAL, A TRANSITION-STATE ALDEHYDE INHIBITOR
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DOI：
10.1111/j.1471-4159.1983.tb11815.x
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发表时间：
1983-01-01
影响因子：
4.7
通讯作者：
ORLOWSKI, M
中科院分区：
文献类型：
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作者：
WILK, S;ORLOWSKI, M
脯氨酰内肽酶切割肽链内脯氨酸残基羧基侧的肽键。该酶很容易降解许多神经肽，包括 P 物质、神经降压素、TRH 和 LHRH。该酶被苯甲氧基羰基-脯氨酰-脯氨酸抑制，Ki为50μM，这一发现促进了苯甲氧基羰基-脯氨酰-脯氨酸作为潜在的过渡态类似物抑制剂的合成。为了这些研究，将兔脑脯氨酰内肽酶纯化至均质。该醛是脯氨酰内肽酶的非常有效的抑制剂，Ki 为 14 nM。该 Ki 比相应酸或醇的 Ki 低 > 3000 倍。通过与其他过渡态抑制剂类比，推测脯氨酸残基与 S1 亚位点的结合以及与酶的活性丝氨酸形成半缩醛极大地有助于抑制效力。多种蛋白酶在比脯氨酰内肽酶 Ki 值高 150 倍的浓度下不受影响，表明了抑制剂的特异性。 Benzyloxycarbonyl-prolyl-prolinal 是脯氨酰内肽酶的特异性且有效的抑制剂，因此它在该酶的生理作用的体内研究中具有价值。
Prolyl endopeptidase cleaves peptide bonds on the carboxyl side of proline residues within a peptide chain. The enzyme readily degrades a number of neuropeptides including substance P, neurotensin, TRH and LHRH. The finding that the enzyme is inhibited by benzyloxycarbonyl-prolyl-proline, with a Ki of 50 .mu.M, prompted the synthesis of benzyloxycarbonyl-prolyl-prolinal as a potential transition state analog inhibitor. Rabbit brain prolyl endopeptidase was purified to homogeneity for these studies. The aldehyde was a remarkably potent inhibitor of prolyl endopeptidase with a Ki of 14 nM. This Ki is > 3000 times lower than that of the corresponding acid or alcohol. By analogy with other transition state inhibitors, it is assumed that binding of the prolinal residue to the S1 subsite and the formation of a hemiacetal with the active serine of the enzyme greatly contribute to the potency of inhibition. The specificity of the inhibitor is indicated by a variety of proteases not affected at concentrations 150 times greater than the Ki for prolyl endopeptidase. Benzyloxycarbonyl-prolyl-prolinal is a specific and potent inhibitor of prolyl endopeptidase and that consequently it should be of value in in vivo studies on the physiological role of the enzyme.