Chandra N, Brew K, Acharya K R
Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
Biochemistry. 1998 Apr 7;37(14):4767-72. doi: 10.1021/bi973000t.
The high-resolution X-ray crystal structure of human alpha-lactalbumin (at 1.8 A) in the presence of an elevated level of calcium reveals a new secondary calcium binding site, 7.9 A away from the primary calcium binding site known in all alpha-lactalbumin structures so far. The new calcium binding site is different from the zinc and sulfate binding sites [Ren, J., et al. (1993) J. Biol. Chem. 268, 19292-19298] but shares common features with the manganese binding site as described by Gerkin [Gerkin, T. A. (1984) Biochemistry 23, 4688-4697]. The proximity of the manganese and calcium binding region and the location of the functional site on one side of the charged surface of the alpha-lactalbumin molecule suggest that these binding sites might play a role in the formation of the lactose synthase complex.
在钙离子水平升高的情况下，人α-乳白蛋白的高分辨率X射线晶体结构（分辨率为1.8埃）揭示了一个新的二级钙结合位点，该位点距离迄今为止在所有α-乳白蛋白结构中已知的一级钙结合位点7.9埃。新的钙结合位点不同于锌和硫酸根结合位点[Ren, J., 等人 (1993) 《生物化学杂志》268, 19292 - 19298]，但与Gerkin所描述的锰结合位点具有共同特征[Gerkin, T. A. (1984) 《生物化学》23, 4688 - 4697]。锰和钙结合区域的接近以及功能位点在α-乳白蛋白分子带电表面一侧的位置表明，这些结合位点可能在乳糖合酶复合物的形成中发挥作用。
