Giambanco I, Pula G, Bianchi R, Donato R
Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Italy.
FEBS Lett. 1990 Jul 2;267(1):171-5. doi: 10.1016/0014-5793(90)80316-b.
CaPB33 and CaPB37, two annexins purified from bovine brain, interact with a Triton X-100-resistant fraction (cytoskeleton) from bovine brain membranes in a Ca2(+)-dependent way in vitro. The binding is saturable with respect to the CaBP33-CaBP37 concentration, half-maximal binding occurring at approximately 15 micrograms of the CaBP33-CaBP37 mixture/ml. The binding of these two annexins to the crude cytoskeleton preparation as a function of free Ca2+ concentration is biphasic, with half-maximal binding at approximately 50 microM and approximately 400 microM free Ca2+ for the first and the second component, respectively. By an overlay technique, CaBP33 and CaBP37 bind to a set of low Mr polypeptides (10-20 kDa) in the crude cytoskeleton preparation, with formation of an 85-90 kDa complex as investigated in cross-linking experiments. No binding of the CaBP33-CaBP37 mixture to either G- or F-actin has been observed. Identification of the CaBP33-CaBP37-binding proteins in cytoskeletons would help elucidating the function(s) of these annexins in the brain.
从牛脑中纯化得到的两种膜联蛋白CaPB33和CaPB37，在体外以Ca2+依赖的方式与牛脑膜的Triton X-100抗性组分（细胞骨架）相互作用。这种结合相对于CaBP33-CaPB37的浓度是可饱和的，在约15微克CaBP33-CaPB37混合物/毫升时出现半数最大结合。这两种膜联蛋白与粗制细胞骨架制剂的结合作为游离Ca2+浓度的函数呈双相性，第一和第二组分的半数最大结合分别在约50微摩尔和约400微摩尔游离Ca2+时出现。通过覆盖技术，CaBP33和CaPB37与粗制细胞骨架制剂中的一组低分子量多肽（10 - 20 kDa）结合，如交联实验所研究的那样形成85 - 90 kDa的复合物。未观察到CaBP33 - CaBP37混合物与G - 肌动蛋白或F - 肌动蛋白的结合。鉴定细胞骨架中CaBP33 - CaBP37结合蛋白将有助于阐明这些膜联蛋白在脑中的功能。
