Odake S, Kam C M, Powers J C
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta 30332-0400, USA.
J Enzyme Inhib. 1995;9(1):17-27. doi: 10.3109/14756369509040678.
Arg-containing peptide chloromethyl ketones including D-Phe-Pro-Arg-CH2Cl derivatives have been synthesized and tested as inhibitors for thrombin and several blood coagulation enzymes. The parent compound, D-Phe-Pro-Arg-CH2Cl is still the best thrombin inhibitor in the series with kobs/[I] value of 10(7) M-1s-1. Extension by one amino acid (Phe or Gly), or a peptide moiety (ClCH2-Arg < -Pro < -D-Phe < -CO-CO-, ClCH2-Arg < -Pro < -D-Phe < -CO-(CH2)3-CO-, where < -indicates a reversed amino acid residue, -CO-CHR-NH-) on the N-terminus of D-Phe-Pro-Arg-CH2Cl reduces the inhibition constant by 1-2 orders of magnitude, which indicates the importance of a free amino group at the N-terminus. The tripeptide D-Phe-Pro-Arg-CH2Cl and related tetrapeptide inhibitors inhibit thrombin more potently than factor IXa and plasma kallikrein by 2-5 orders of magnitude. Z-Arg-CH2Cl and Phe-Phe-Arg-CH2Cl which contain a large hydrophobic group at the P2 site inhibit thrombin poorly. All the peptide chloromethyl ketones inhibit plasma kallikrein moderately with kobs/[I] values of 10(2)-10(3) M-1s-1 but inhibit factor IXa poorly (kobs/[I] < 20 M-1s-1). Conjugates of albumin with the bis chloromethyl ketones [(CO-D-Phe-Pro-Arg-CH2Cl)2, (CH2)3-(CO-D-Phe-Pro-Arg-CH2Cl)2] were prepared and are potent thrombin inhibitors. These conjugates are model compounds for developing specific thrombus-bound thrombin inhibitors which may have therapeutic application in the treatment of coagulation disorders.
已合成了含精氨酸的肽氯甲基酮，包括D - 苯丙氨酸 - 脯氨酸 - 精氨酸 - CH₂Cl衍生物，并作为凝血酶和几种血液凝固酶的抑制剂进行了测试。母体化合物D - 苯丙氨酸 - 脯氨酸 - 精氨酸 - CH₂Cl仍然是该系列中最佳的凝血酶抑制剂，其kobs/[I]值为10⁷ M⁻¹s⁻¹。在D - 苯丙氨酸 - 脯氨酸 - 精氨酸 - CH₂Cl的N端延伸一个氨基酸（苯丙氨酸或甘氨酸）或一个肽部分（ClCH₂ - 精氨酸 < - 脯氨酸 < - D - 苯丙氨酸 < - CO - CO - ，ClCH₂ - 精氨酸 < - 脯氨酸 < - D - 苯丙氨酸 < - CO - (CH₂)₃ - CO - ，其中 < - 表示氨基酸残基反向， - CO - CHR - NH - ）可使抑制常数降低1 - 2个数量级，这表明N端游离氨基的重要性。三肽D - 苯丙氨酸 - 脯氨酸 - 精氨酸 - CH₂Cl和相关的四肽抑制剂对凝血酶的抑制作用比因子IXa和血浆激肽释放酶强2 - 5个数量级。在P2位点含有大的疏水基团的Z - 精氨酸 - CH₂Cl和苯丙氨酸 - 苯丙氨酸 - 精氨酸 - CH₂Cl对凝血酶的抑制作用较差。所有的肽氯甲基酮对血浆激肽释放酶有中等程度的抑制作用，kobs/[I]值为10² - 10³ M⁻¹s⁻¹，但对因子IXa的抑制作用较差（kobs/[I] < 20 M⁻¹s⁻¹）。制备了白蛋白与双氯甲基酮[（CO - D - 苯丙氨酸 - 脯氨酸 - 精氨酸 - CH₂Cl）₂，（CH₂）₃ - （CO - D - 苯丙氨酸 - 脯氨酸 - 精氨酸 - CH₂Cl）₂]的缀合物，它们是有效的凝血酶抑制剂。这些缀合物是开发特异性血栓结合凝血酶抑制剂的模型化合物，可能在凝血障碍的治疗中具有治疗应用。
