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[Binding to chicken liver lactatedehydrogenase (author's transl)]
Revista Espanola De Fisiologia
|June 1, 1976
Summary
Chicken liver lactate dehydrogenase (LDH) enzyme activity is inhibited by coenzyme analogs. Specificity for adenine groups at the enzyme binding site was observed, with phosphate presence being crucial for binding.
Area of Science:
- Biochemistry
- Enzymology
- Molecular Biology
Context:
- Lactate dehydrogenase (LDH) is a crucial enzyme in cellular metabolism.
- Understanding the NAD binding site of LDH is key to enzyme mechanism studies.
- Coenzyme analogs are valuable tools for probing enzyme active sites.
Purpose:
- To investigate the binding characteristics of various coenzyme analogs to the NAD binding site of chicken liver lactate dehydrogenase.
- To determine the structural requirements for coenzyme analog binding to LDH.
- To elucidate the specificity of the LDH active site for different components of its coenzyme, NADH.
Summary:
- Chicken liver LDH activity was competitively inhibited by several adenosine-based coenzyme analogs, including 5'AMP, 5'-ADP, ATP, 5'-c-AMP, and 3'(2)-AMP.
- The presence of one or two phosphate groups on adenosine (5'-AMP, 5'-ADP) was essential for strong binding, while ribose or adenine-less nucleotides did not inhibit activity.
- Replacing ribose with glucose (5"-ADPG) did not significantly affect binding, but the absence of hydroxyl groups (2'-deoxyadenosine-5'-phosphate) reduced inhibitory potency, suggesting interactions with active site amino acids.
Impact:
- This study provides insights into the structural determinants of coenzyme binding at the LDH active site.
- Findings highlight the specificity of LDH for the adenine moiety and the importance of phosphorylation for binding.
- The results contribute to a deeper understanding of enzyme-coenzyme interactions and can inform the design of enzyme inhibitors.