采用两种不同方法获得的脉红螺血蓝蛋白低分子量片段的比较结构分析。

Comparative structural analysis of low-molecular mass fragments of Rapana venosa hemocyanin obtained using two different procedures.

作者信息

Sabatucci Annalaura, Vachette Patrice, Beltramini Mariano, Salvato Benedetto, Dainese Enrico

机构信息

Department of Biomedical Sciences, University of Teramo, Piazza A. Moro 45, 64100 Teramo, Italy.

出版信息

J Struct Biol. 2005 Feb;149(2):127-37. doi: 10.1016/j.jsb.2004.10.004.

DOI:10.1016/j.jsb.2004.10.004

PMID:15681229

Abstract

Different fragments of the hemocyanin (Hc) isolated from the gastropod Rapana venosa containing a single functional unit (50 kDa), two functional units (100 kDa) and three functional units (150 kDa) were obtained in a dissociating buffer in the presence of Zn2+ and purified to homogeneity. Their conformations in solution were studied by means of small angle X-ray scattering (SAXS) and compared with those of the corresponding fragments previously obtained by limited proteolysis [Arch. Biochem. Biophys., 2000, 373, 154]. The overall shape of each fragment was determined using an ab initio approach. The crystal structures of the functional unit e from the same Hc and from another molluscan Hc (Octopus dofleini) were used to model 100 and 150 kDa fragments using rigid body movements to fit the corresponding SAXS patterns. Interesting differences were observed between the functional unit organization in the low-molecular mass fragments according to the two preparation methods, suggesting different localizations within the 11S functional subunit.

摘要

从脉红螺中分离出的血蓝蛋白（Hc）含有单个功能单元（50 kDa）、两个功能单元（100 kDa）和三个功能单元（150 kDa）的不同片段，在含Zn2+的解离缓冲液中获得，并纯化至同质。通过小角X射线散射（SAXS）研究了它们在溶液中的构象，并与之前通过有限蛋白酶解获得的相应片段的构象进行了比较[《生物化学与生物物理学档案》，2000年，373卷，第154页]。使用从头算方法确定了每个片段的整体形状。来自同一Hc和另一种软体动物Hc（北太平洋巨型章鱼）的功能单元e的晶体结构被用于通过刚体运动对100 kDa和150 kDa片段进行建模，以拟合相应的SAXS模式。根据两种制备方法，在低分子量片段中的功能单元组织之间观察到有趣的差异，这表明在11S功能亚基内存在不同的定位。