Pseudocatalase from Lactobacillus plantarum: evidence for a homopentameric structure containing two atoms of manganese per subunit
- 1 November 1985
- journal article
- research article
- Published by American Chemical Society (ACS) in Biochemistry
- Vol. 24 (23), 6460-6467
- https://doi.org/10.1021/bi00344a023
Abstract
An improved procedure for the isolation of the pseudocatalase of Lactobacillus plantarum has been devised, and the quaternary structure and manganese content of this enzyme have been reexamined. Sedimentation equilibrium of the native enzyme at several salt concentrations gave a molecular weight of 172,000. The subunit weight, obtained by sedimentation equilibrium in 6.4 M guanidinium chloride, with or without prior reduction and carboxymethylation, was 34 kilodaltons. The amino acid composition indicated 150 Arg + Lys, and after exhaustive tryptic digestion, 32 peptides were resolved. These data suggest that the pseudocatalase is a homopentamer. Cross-linking with dimethyl suberimidate, followed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, yielded five major bands, another indication of pentameric structure. The manganese content was found to be 1.8-2.4 per subunit. s20,w was found to be 9.6 S and f/f0 = 1.2, suggesting a globular structure of Stokes radius 44 .ANG.This publication has 1 reference indexed in Scilit:
- Properties of Human Erythrocyte Catalases after Crosslinking with Bifunctional Reagents Symmetry of the Quaternary StructureEuropean Journal of Biochemistry, 1977