Cu(Ⅱ)-家蚕丝素蛋白质配合物的配位结构和高次结构

Coordination Structure and Higher Order Structure of Cu(Ⅱ)-Silk Fibroin Protein(Bombyx Mori) Complexes

家蚕丝素蛋白质在不同 p H条件下经均相和不均相配位反应制备了 Cu( ) -丝素配合物 ,用可见光谱、电子自旋共振波谱 ( ESR)、 X射线衍射 ( XRD)研究了其配位结构和高次结构 .在碱性条件下 ( p H=1 0 .60 ) ,丝素肽链主链的 4个氮原子螯合 Cu( )生成具有近似平面四方 Cu( N) 4结构的配合物 ;而在酸性条件下 ( p H=4 .3 0 ,5.88) ,主要是丝素肽链的侧 (端 )基羧酸根键合 Cu( )生成 Cu( ) (—COO— ) ( H2 O) 3和 Cu( ) (— COO— ) 2 型配合物 .讨论和描述了不同条件下生成的 Cu( )

The copper(Ⅱ) complexes of silk fibroin protein of Bombyx mori are prepared by homogeneous and heterogeneous phase coordination reaction at different pH values, and their coordination structures and aggregated structures are investigated by means of spectroscopy, electron spin resonance(ESR) and Xray diffraction(XRD) measurements. Under the basic condition (pH=10.60), one type of complex is formed which contains four nitrogens from peptide main chain at the corners of a square in which the copper(Ⅱ) occupies the center, and while under the acid condition(pH=430, 588), other complex is obtained, which is mainly formed by the carboxyl of peptide side or end groups binding copper(Ⅱ) as Cu(Ⅱ)· (—COO—) (H 2O) 3 and Cu(Ⅱ)(—COO—) 2. The higher order structures of Cu(Ⅱ)silk fibroin protein complexes prepared under various conditions are also discussed and described.