Soluble malate dehydrogenase of Geophagus brasiliensis (Cichlidae, Perciformes): isolated isoforms and kinetics properties

Genetics and Molecular Biology

Maria Regina De Aquino-silva²  Maria Luiza Barcellos Schwantes¹  Flavia Simone Munin¹  Arno Rudi Schwantes¹  Silvana Pereira Dos Santos² 

[1] ,Universidade do Vale do Paraíba Instituto de Pesquisa & Desenvolvimento São José dos Campos SP ,Brazil

关键词: gene duplication;    sMDH;    substrate concentration;    temperature;    pH isoforms;   

DOI  :  10.1590/S1415-47572008000200029

来源: SciELO

【 摘 要 】

Kinetic properties and thermal stabilities of Geophagus brasiliensis skeletal muscle unfractionated malate dehydrogenase (MDH, EC 1.1.1.37) and its isolated isoforms were analyzed to examine a possible sMDH-B* locus duplication in a fixation process influenced by genetic drift. Two optimal pHs were detected: 7.5 for AB1 unfractionated muscle phenotype and its B1 isoform, and 8.0 for AB1B2 unfractionated muscle phenotype, A and B2 isoforms. While G. brasiliensis A isoform could be characterized as thermostable, the duplicated B isoform cannot be assumed as thermolabile. Km values for isolated B2 isoforms were 1.6 times lower than for B1. A duplication event in progress best explains the electrophoretic six-band pattern detected in G. brasiliensis, which would be caused by genetic drift.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License