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Sequential model

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The sequential model (also known as the KNF model ) is a theory that describes co-operativity of protein subunits[1]

Overview

This model for allosteric regulation of enzymes suggests that the subunits of multimeric proteins have two conformational states. The binding of the ligand causes conformational change in the other subunits of the multimeric protein. Although the subunits go through conformational changes independently (as opposed to in the MWC model) the switch of one subunit makes the other subunits more likely to change, by reducing the energy needed for subsequent subunits to undergo the same conformational change. In elaboration, the binding of a ligand to one subunit changes the protein's shape, thereby making it more thermodynamically favourable for the other subunits to switch conformation to the high affinity state. Ligand binding may also result in negative cooperativity, or a reduced affinity for the ligand at the next binding site, a feature that makes the KNF model distinct from the MWC model, which only offers positive cooperativity.[2] It is named KNF after Koshland, Némethy and Filmer.

References

  1. ^ Koshland, D.E., Némethy, G. and Filmer, D. (1966) Comparison of experimental binding data and theoretical models in proteins containing subunits. Biochemistry 5, 365–385. DOI: 10.1021/bi00865a047
  2. ^ Koshland, Daniel E.; Hamadani, Kambiz (2002-12-06). "Proteomics and Models for Enzyme Cooperativity". Journal of Biological Chemistry. 277 (49): 46841–46844. doi:10.1074/jbc.R200014200. ISSN 0021-9258. PMID 12189158.{{cite journal}}: CS1 maint: unflagged free DOI (link)

Dr. Matt Higgins, 'Protein structure and function', 2006 (Thesis? Article? Book?)