Characterization of the kinetics and activation thermodynamics of intra- and inter-organism hybrid tetramers of pyruvate carboxylase

Abdussalam Adina-Zada, Sarawut Jitrapakdee, Paul V. Attwood

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

In sedimentation velocity experiments, we have been able to detect hybrid Rhizobium etli pyruvate carboxylase tetramers formed between subunits that contain covalently bound biotin and mutant subunits that do not. This was performed by forming complexes of the tetramers with the biotin-binding protein avidin. In addition, we have shown that it is possible to form hybrid tetramers of pyruvate carboxylase subunits from two different organisms (bacteria - Rhizobium etli and fungi – Aspergillus nidulans). In hybrid tetramers containing mutant subunits that are not fully catalytically active and fully catalytically active subunits, the catalytic and regulatory properties of these hybrid tetramers are modified compared to homotetramers of the fully active pyruvate carboxylase subunits. Our data indicates that the model of catalysis involving half-of-the-sites activity in which there is obligatory alternation of pyruvate carboxylating activity between pairs of subunits either face of the tetramer, does not occur in the hybrid tetramers. Our results are also discussed in relation to recent findings that there are multiple pathways of biotin carboxylation and decarboxylation between subunits in pyruvate carboxylase tetramers.

Original languageEnglish
Pages (from-to)87-95
Number of pages9
JournalArchives of Biochemistry and Biophysics
Volume665
DOIs
Publication statusPublished - 15 Apr 2019

Fingerprint Dive into the research topics of 'Characterization of the kinetics and activation thermodynamics of intra- and inter-organism hybrid tetramers of pyruvate carboxylase'. Together they form a unique fingerprint.

Cite this