Heterogeneity of quaternary structure of glucosamine-6-phosphate deaminase from Giardia lamblia.

ABSTRACT: The oligoHis-tagged versions of glucosamine-6-phosphate deaminase from Giardia lamblia (GlmNagB-HisN, GlmNagB-HisC) were constructed and purified to hear homogeneity, and their kinetic and structural properties were compared to those of the wild-type enzyme (GlmNagB). Introduction of the oligoHis tag at the GlmNagB C-terminus resulted in almost complete loss of the catalytic activity, while the catalytic properties of GlmNagB-HisN and GlmNagB were very similar. The recombinant and wild-type enzyme exhibits heterogeneity of the quaternary structure and in solution exists in three interconvertible forms, namely, monomeric, homodimeric, and homotetrameric. Although the monomeric form is prevalent, the monomer/dimer/tetramer ratios depended on protein concentration and fell within the range fr

SUBMITTER: Kwiatkowska-Semrau K 

PROVIDER: S-EPMC4281351 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature