Bluhm Martin E, Kim Sanggoo S, Dertz Emily A, Raymond Kenneth N
Department of Chemistry, University of California, Berkeley, CA 94720-1460, USA.
J Am Chem Soc. 2002 Mar 20;124(11):2436-7. doi: 10.1021/ja016651s.
Most species of bacteria employ siderophores to acquire iron. The chirality of the ferric siderophore complex plays an important role in cell recognition, uptake, and utilization. Corynebactin, isolated from Gram-positive bacteria, is structurally similar to enterobactin, a well known siderophore isolated from Gram-negative bacteria, but contains L-theronine instead of L-serine in the trilactone backbone. Corynebactin also contains a glycine spacer unit in each of the chelating arms. A hybrid analogue (serine-corynebactin) has been synthesized. The chirality and relative conformational stability of the three ferric complexes of enterobactin, corynebactin, and the hybrid has been investigated. In contrast to enterobactin, corynebactin assumes a Lambda configuration. However, the ferric serine-corynebactin hybrid forms a racemic mixture, only slightly favoring the Lambda conformation.
大多数细菌种类利用铁载体来获取铁。铁载体-铁复合物的手性在细胞识别、摄取和利用中起着重要作用。从革兰氏阳性菌中分离出的棒状杆菌素在结构上与从革兰氏阴性菌中分离出的一种著名铁载体肠杆菌素相似，但在三内酯主链中含有L-苏氨酸而非L-丝氨酸。棒状杆菌素在每个螯合臂中还含有一个甘氨酸间隔单元。已合成了一种杂合类似物（丝氨酸-棒状杆菌素）。对肠杆菌素、棒状杆菌素和该杂合物的三种铁复合物的手性和相对构象稳定性进行了研究。与肠杆菌素不同，棒状杆菌素呈λ构型。然而，铁-丝氨酸-棒状杆菌素杂合物形成外消旋混合物，仅略微倾向于λ构象。
