Kang Y K, Yoo S H
Laboratory of Neurochemistry, NIDCD, National Institutes of Health, Bethesda, MD 20892-3320, USA.
FEBS Lett. 1997 Mar 3;404(1):87-90. doi: 10.1016/s0014-5793(97)00099-9.
Since the conserved near N-terminal region (residues 18-37) of chromogranin A (CGA) has tentatively been identified as the vesicle membrane interacting region using synthetic peptides, it was necessary to confirm this finding with CGA deletion proteins. In order to address this need and to clarify the discrepancies of the published amino acid sequences of CGA, we cloned a CGA gene and produced CGA deletion proteins of various sizes. The recombinant CGA protein lacking the first 16 amino acid residues bound to the vesicle membrane as well as the full-length CGA at pH 5.5. However, the CGA protein lacking the first 39 amino acid residues, which include the conserved near N-terminal region (residues 17-38), failed to interact with the vesicle membrane at pH 5.5, clearly indicating the essential role of the conserved near N-terminal region in the pH-dependent interaction of CGA with the vesicle membrane.
由于使用合成肽初步确定嗜铬粒蛋白A（CGA）保守的近N端区域（第18 - 37位氨基酸残基）为囊泡膜相互作用区域，因此有必要用CGA缺失蛋白来证实这一发现。为满足这一需求并澄清已发表的CGA氨基酸序列的差异，我们克隆了一个CGA基因并制备了各种大小的CGA缺失蛋白。在pH 5.5时，缺少前16个氨基酸残基的重组CGA蛋白与囊泡膜结合，与全长CGA一样。然而，缺少前39个氨基酸残基（包括保守的近N端区域，第17 - 38位氨基酸残基）的CGA蛋白在pH 5.5时未能与囊泡膜相互作用，这清楚地表明保守的近N端区域在CGA与囊泡膜的pH依赖性相互作用中起关键作用。
