人类超氧化物歧化酶中的熔球态单体

Molten globule monomers in human superoxide dismutase.

作者信息

Silva N, Gratton E, Mei G, Rosato N, Rusch R, Finazzi-Agrò A

机构信息

Mayo Clinic, Rochester, MN 55905.

出版信息

Biophys Chem. 1993 Dec;48(2):171-82. doi: 10.1016/0301-4622(93)85008-6.

DOI:10.1016/0301-4622(93)85008-6

PMID:8298055

Abstract

The time-resolved fluorescence decay and anisotropy of Cu/Zn human superoxide dismutase (HSOD) were studied as a function of temperature and denaturant concentration. In addition, circular dichroism (CD) measurements were performed on HSOD as a function of denaturant concentration in the amide and aromatic regions. The time-resolved fluorescence decay results reveal the existence of structural microheterogeneity in HSOD. Furthermore, CD measurements and a global analysis decomposition of the time-resolved fluorescence decay over denaturant concentration shows the presence of an intermediate in the unfolding of HSOD by guanidinium hydrochloride. Considering our previous measurements of partially denatured HSOD as a function of protein concentration (Mei et al., Biochemistry 31 (1992) 7224-7230), our results strongly suggest that the unfolding intermediate is a monomer that displays a molten globule state.

摘要

研究了铜/锌人超氧化物歧化酶（HSOD）的时间分辨荧光衰减和各向异性随温度和变性剂浓度的变化。此外，还对HSOD在酰胺和芳香区域进行了圆二色性（CD）测量，测量结果随变性剂浓度而变化。时间分辨荧光衰减结果揭示了HSOD中存在结构微不均一性。此外，CD测量以及变性剂浓度下时间分辨荧光衰减的全局分析分解表明，盐酸胍使HSOD展开过程中存在一个中间体。结合我们之前对部分变性的HSOD随蛋白质浓度变化的测量结果（Mei等人，《生物化学》31卷（1992年）7224 - 7230页），我们的结果有力地表明，展开中间体是一种呈现熔球态的单体。