Vancompernolle K, Vandekerckhove J, Bubb M R, Korn E D
Laboratory of Physiological Chemistry, State University of Ghent, Belgium.
J Biol Chem. 1991 Aug 15;266(23):15427-31.
Actobindin is an 88-amino acid polypeptide, containing two almost identical repeated domains of 33 and 34 residues. Depending on the molar ratios in which they are mixed, actobindin binds either one or two actin molecules. We cross-linked actobindin and actin in the 1:1 complex, using the zero-length cross-linker 1-ethyl-3(3-dimethylaminopropyl)carbodiimide. The cross-linked peptides were purified after consecutive CNBr cleavage and trypsin and Staphylococcus protease V8 digestions, and the cross-linked side chains were identified by amino acid sequencing. Isopeptide linkages were formed between residues Glu-100 of actin and Lys-16 of actobindin. In addition, we found a connection between one or more of the acidic residues 1,2, or 3 of actin and Lys-16 and Lys-52 of actobindin. The cross-linked regions in actobindin contain Leu-Lys-His-Ala-Glu-Thr motifs, similar to sequences observed in several other actin-binding proteins.
肌动蛋白结合蛋白是一种由88个氨基酸组成的多肽，包含两个几乎相同的重复结构域，分别有33个和34个残基。根据混合时的摩尔比，肌动蛋白结合蛋白可结合一个或两个肌动蛋白分子。我们使用零长度交联剂1-乙基-3（3-二甲基氨基丙基）碳二亚胺，将肌动蛋白结合蛋白和肌动蛋白交联形成1:1复合物。交联后的肽段经过连续的溴化氰裂解、胰蛋白酶和葡萄球菌蛋白酶V8消化后进行纯化，并通过氨基酸测序鉴定交联的侧链。在肌动蛋白的Glu-100残基和肌动蛋白结合蛋白的Lys-16残基之间形成了异肽键。此外，我们还发现肌动蛋白的酸性残基1、2或3中的一个或多个与肌动蛋白结合蛋白的Lys-16和Lys-52之间存在联系。肌动蛋白结合蛋白中的交联区域包含Leu-Lys-His-Ala-Glu-Thr基序，类似于在其他几种肌动蛋白结合蛋白中观察到的序列。
