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Cobalt and corrinoid transport and biochemistry
Valentin Cracan1, Ruma Banerjee
1Department of Biological Chemistry, University of Michigan, 4220C MSRB III, 1150 W. Medical Center Dr., Ann Arbor, MI, 48109-0600, USA, vfcracan@umich.edu.
Metal Ions in Life Sciences
|April 19, 2013
Summary
This chapter explores cobalt biochemistry in enzymes, including non-corrin cobalt and corrinoid-dependent enzymes like nitrile hydratase and acyl-CoA mutases. It highlights cofactor loading mechanisms for adenosylcobalamin-dependent enzymes.
Area of Science:
- Biochemistry
- Enzymology
- Bioinorganic Chemistry
Background:
- Cobalt is essential in biological systems, playing a key role in both non-corrin and corrinoid-containing enzymes.
- Corrinoid cofactors, particularly alkylcorrinoids, utilize the cobalt-carbon bond for complex chemical transformations.
- Adenosylcobalamin (AdoCbl) is crucial for radical-based catalysis in enzymes like acyl-CoA mutases.
Purpose of the Study:
- To review the biochemistry of non-corrin cobalt and corrinoid-dependent enzymes.
- To discuss cobalt and corrinoid import in prokaryotes.
- To explore the function and cofactor loading mechanisms of adenosylcobalamin-dependent enzymes.
Main Methods:
- Literature review of cobalt biochemistry.
- Discussion of specific enzyme families: nitrile hydratase, methionine aminopeptidase, and acyl-CoA mutases.
- Analysis of chaperone-mediated cofactor loading for AdoCbl-dependent enzymes.
Main Results:
- Cobalt is vital for enzymes catalyzing challenging biotransformations via non-corrin and corrinoid cofactors.
- Acyl-CoA mutases represent a rapidly expanding subfamily of AdoCbl-dependent enzymes.
- G-protein chaperones ensure accurate cofactor loading for AdoCbl-dependent enzymes through GTP hydrolysis.
Conclusions:
- Understanding cobalt biochemistry is key to deciphering diverse enzymatic functions.
- The precise regulation of cofactor loading by chaperones is critical for enzyme activity and fidelity.
- This work provides insights into the intricate mechanisms of cobalt-dependent enzymatic catalysis.
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