Cabaniss S E, Pugh K C, Charifson P S, Pedersen L G, Hiskey R G
Department of Chemistry, University of North Carolina, Chapel Hill.
Int J Pept Protein Res. 1990 Jul;36(1):79-85. doi: 10.1111/j.1399-3011.1990.tb00085.x.
1,1,4,4-Butanetetracarboxylic acid (BTCA) is evaluated as an analogue for the metal binding site in dipeptides of gamma-carboxyglutamic acid (Gla). Molecular modeling suggests that the four carboxylic acid groups in BTCA can assume a similar conformation to the four gamma-carboxylic acid groups in GlaGla and thus provides the impetus for the synthesis and metal binding determinations. BTCA is synthesized via the tert.-butyl ester and characterized via NMR, mass spectroscopy, and elemental composition. Equilibrium binding constants with protons, Ca(II) and Mg(II) are determined via pH and Ca(II) ion-selective electrode titrations and are found to be similar to those for GlaGla peptides with blocked termini.
1,1,4,4-丁烷四羧酸（BTCA）被评估为γ-羧基谷氨酸（Gla）二肽中金属结合位点的类似物。分子模型表明，BTCA中的四个羧酸基团可以呈现出与GlaGla中的四个γ-羧酸基团相似的构象，从而为合成和金属结合测定提供了动力。BTCA通过叔丁酯合成，并通过核磁共振、质谱和元素组成进行表征。通过pH值和Ca（II）离子选择性电极滴定法测定了与质子、Ca（II）和Mg（II）的平衡结合常数，发现其与末端封闭的GlaGla肽的平衡结合常数相似。
