R－藻红蛋白──金（AUC4）和汞（PCMS）重原子衍生物的制备和分析

在获得适合Ｘ射线衍射分析用的Ｒ－藻红蛋白单晶体的基础上，用重原子浸泡法，将晶体浸入含重金属金和汞的０．０５ｍｏｌ／Ｌ磷酸钠－硫酸铵的母液内，经对晶体衍射点强度的分析。找出有明显变化的重原子衍生物。最终得到了与Ｒ－藻红蛋白晶体同晶型的含金和汞的两种重原子衍生物。用面探测仪分别惧了这两种重原子衍生物的衍射数据。通过差值Ｐａｔｔｅｒｓｏｎ图分析，分别确定了重金属金和汞的位置，经对重原子位置参数精化化，给

PREPARATION OF HEAVY ATOM DERIVATIVES OF R-PHYCOERYTHRIN CRYSTAL FROM POLYSIPHONIA URCEOLATA

On the basis of growing single Crystals suitable for X-ray analysis, two heary atom derivatives of R-Phycoerythin(R-PE) have been obtained in 0.05mol/L sodium phosphate buffer and (NH4)2SO4 system containing K2AuCl4 and P-chloromercuriphyl sulphonic acid reagents by soaking native crystals method. Changes in X-ray diffraction pattern using Buerger's processing photograph were found. The data of native and both derivatives of R-PE crystals were collected on Siemens X-200B area detector diffractometor. The positions of gold and mercury atoms were determined by using Patterson difference analysis. The Figure of merit of both heavy atom parameters showed that native phases can be obtained by the multiple isomorphous replacement method.