棘孢曲霉内切葡聚糖酶的结晶及初步X射线衍射研究

Crystallization and preliminary X-ray diffraction studies of an endoglucanase from Aspergillus aculeatus.

作者信息

Hata Y, Natori K, Katsube Y, Ooi T, Arai M, Okada H

机构信息

Institute for Chemical Research, Kyoto University, Japan.

出版信息

J Mol Biol. 1994 Aug 12;241(2):278-80. doi: 10.1006/jmbi.1994.1499.

DOI:10.1006/jmbi.1994.1499

PMID:8057368

Abstract

Most fungal cellulases are found in multiple forms varying in size and substrate specificity. Aspergillus aculeatus is known to produce nine cellulolytic enzymes including an endoglucanase (FI CM-cellulase, M(r) = 24,002) as the major component. Single crystals of FI CM-cellulase from Aspergillus aculeatus have been prepared by sitting-drop vapour diffusion using ammonium sulphate as a precipitant. The cellulase crystals belong to the orthorhombic space group P2(1)2(1)2(1) with unit cell dimensions of a = 52.79(2) A, b = 106.40(4) A and c = 33.15(1) A. The crystals contain one enzyme molecule per asymmetric unit. They diffract to at least 2.0 A resolution and are very stable against X-ray irradiation.

摘要

大多数真菌纤维素酶以多种形式存在，其大小和底物特异性各不相同。已知棘孢曲霉能产生九种纤维素分解酶，其中一种内切葡聚糖酶（FI CM - 纤维素酶，M(r) = 24,002）是主要成分。利用硫酸铵作为沉淀剂，通过悬滴气相扩散法制备了来自棘孢曲霉的FI CM - 纤维素酶单晶。该纤维素酶晶体属于正交晶系空间群P2(1)2(1)2(1)，晶胞参数为a = 52.79(2) Å，b = 106.40(4) Å，c = 33.15(1) Å。每个不对称单元包含一个酶分子。它们的衍射分辨率至少为2.0 Å，并且对X射线照射非常稳定。