Synthetic peptides as inactivators of multimeric enzymes: inhibition of Plasmodium falciparum triosephosphate isomerase by interface peptides

Singh, Kumar S and Maithal, Kapil and Balaram, Hemalatha and Balaram, P (2001) Synthetic peptides as inactivators of multimeric enzymes: inhibition of Plasmodium falciparum triosephosphate isomerase by interface peptides. In: FEBS Letters, 501 (1). pp. 19-23.

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Abstract

Synthetic peptides corresponding to two distinct segments of the subunit interface of the homodimeric enzyme triosephosphate isomerase (residues 9–18, ANWKCNGTLE, peptide I; residues 68–79, KFGNGSYTGEVS, peptide II) from Plasmodium falciparum (PfTIM) have been investigated for their ability to act as inhibitors by interfering with the quaternary structure of the enzyme. An analog of peptide II containing cysteine at the site corresponding to position 74 and tyrosine at position 69 in the protein sequence KYGNGSCTGEVS (peptide III) was also investigated. A substantial fall in enzyme activity was observed following incubation of the enzyme with peptide II, whereas peptide I did not show any appreciable inhibition. The inhibitory effect was more pronounced on two mutants of PfTIM (Y74C and Y74G), both of which have reduced stability compared to the wild-type protein due to an interface cavity. The IC50 value determined for peptide II is in the range of 0.6–0.8 micro M. This study suggests that interface peptides of oligomeric enzymes can be used to inhibit dimeric enzymes by disrupting their native multimeric states and may provide lead structures for potential inhibitor design.

Item Type:	Journal Article
Publication:	FEBS Letters
Publisher:	Elsevier
Additional Information:	Copyright for this article belongs to Elsevier Science Ltd
Keywords:	Malaria;Interface peptide;Enzyme inhibition;Plasmodium falciparum triosephosphate isomerase
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	20 Aug 2004
Last Modified:	19 Sep 2010 04:14
URI:	http://eprints.iisc.ac.in/id/eprint/1313

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