Abergel Rebecca J, Moore Evan G, Strong Roland K, Raymond Kenneth N
Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
J Am Chem Soc. 2006 Aug 30;128(34):10998-9. doi: 10.1021/ja062476+.
The mammalian protein siderocalin binds and inactivates the ferric complex of the bacterial siderophore enterobactin with a Kd value similar to that of the bacterial receptor FepA. However, microorganisms can evade this immune response by structural modifications of the siderophore. The binding of siderophores by siderocalin relies in part on electrostatic interactions and does not depend greatly on what metal is in the complex. It is also sterically limited by the rigid conformation of the protein calyx; methylation of the three catecholate rings of enterobactin hinders siderocalin recognition. The siderocalin binding has been probed for a series of enterobactin analogues in order to investigate in detail the specificity of siderocalin recognition.
哺乳动物蛋白铁调素能结合细菌铁载体肠杆菌素的铁复合物并使其失活，其解离常数（Kd）值与细菌受体FepA的Kd值相似。然而，微生物可通过铁载体的结构修饰来逃避这种免疫反应。铁调素与铁载体的结合部分依赖于静电相互作用，且在很大程度上不取决于复合物中所含的金属。它还受到蛋白萼刚性构象的空间限制；肠杆菌素三个儿茶酚环的甲基化会阻碍铁调素的识别。为了详细研究铁调素识别的特异性，已对一系列肠杆菌素类似物进行了铁调素结合研究。
