A LOW-BARRIER HYDROGEN-BOND IN THE CATALYTIC TRIAD OF SERINE PROTEASES
A LOW-BARRIER HYDROGEN-BOND IN THE CATALYTIC TRIAD OF SERINE PROTEASES
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DOI：
10.1126/science.7661899
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发表时间：
1994-06-24
期刊：
影响因子：
56.9
通讯作者：
TOBIN, JB
中科院分区：
文献类型：
--
作者：
FREY, PA;WHITT, SA;TOBIN, JB
胰凝乳蛋白酶和模型化合物的光谱性质表明，低势垒氢键参与丝氨酸蛋白酶的作用机制。胰凝乳蛋白酶中His（57）的N δ 1和Asp（102）的β-羧基之间的低势垒氢键可以促进四面体加合物的形成，并且该质子的核磁共振性质表明它是低势垒氢键。这些结论得到支持的化学位移的质子，氘同位素效应的化学位移，和氢键模型化合物在有机溶剂中，包括在顺式-尿刊酸，其中咪唑环是内部氢键的羧基基团的氢键的性质。
Spectroscopic properties of chymotrypsin and model compounds indicate that a low-barrier hydrogen bond participates in the mechanism of serine protease action. A low-barrier hydrogen bond between N delta 1 of His(57) and the beta-carboxyl group of Asp(102) in chymotrypsin can facilitate the formation of the tetrahedral adduct, and the nuclear magnetic resonance properties of this proton indicate that it is a low-barrier hydrogen bond. These conclusions are supported by the chemical shift of this proton, the deuterium isotope effect on the chemical shift, and the properties of hydrogen-bonded model compounds in organic solvents, including the hydrogen bond in cis-urocanic acid, in which the imidazole ring is internally hydrogen-bonded to the carboxyl group.