van Batenburg O D, Voskuyl-Holtkamp I, Schattenkerk C, Hoes K, Kerling K E, Havinga E
Biochem J. 1977 May 1;163(2):385-7. doi: 10.1042/bj1630385.
S-peptide (residues 1--14) analogues in which the active histidine-12 residue is replaced by Npi-methyl-L-histidine, Ntau-methyl-L-histidine and beta-(pyrid-3-yl)-L-alanine were synthesized and tested for their capacity to bind to S-protein and to activate it. The results show that both imidazolyl nitrogen atoms are required for optimal catalytic functioning, Ntau being essential to the catalytic reaction itself, Npi playing a role in keeping the imidazole ring in the correct position.
合成了活性组氨酸-12残基被N-甲基-L-组氨酸、N-甲基-L-组氨酸和β-(吡啶-3-基)-L-丙氨酸取代的S-肽（1-14位残基）类似物，并测试了它们与S-蛋白结合和激活S-蛋白的能力。结果表明，两个咪唑基氮原子对于最佳催化功能都是必需的，N-对于催化反应本身至关重要，N-在使咪唑环保持在正确位置方面发挥作用。
