The human immunodeficiency virus type 1 aspartyl protease (HIV-1 PR) is a homodimeric aspartyl endopeptidase that is required for virus replication. HIV-1 PR was shown to act invitro as acyl-donor and -acceptor for both guinea pig liver transglutaminase (TG, EC 2.3.2.13) and human Factor XIIIa. These preliminary evidences suggested that the HIV-1 PR contains at least three TG-reactive glutaminyl and one lysyl residues. We report here that the incubation of HIV-1 PR with TG increases its catalytic activity. This increase is dependent upon the time of incubation, the concentration of TG and the presence of Ca2+. Identification of epsilon-(gamma-glutamyl)lysine in the proteolytic digest of the TG-modified HIV-1 PR suggested intramolecular covalent cross-linking of this protease which may promote a non-covalent dimerization and subsequent activation of this enzyme via a conformational change. This hypothesis is supported by the observation that the TG-catalyzed activation of HIV-1 PR was completely abolished by spermidine (SPD) which acts as a competitive inhibitor of epsilon-(gamma-glutamyl)lysine formation. Indeed, in the presence of 1mM SPD the formation of the isopeptide was decreased of about 80%. The main products of the TG-catalyzed modification of HIV-1 PR in the presence of SPD were N(1)-mono(gamma-glutamyl)SPD and N(8)-mono(gamma-glutamyl)SPD. Negligible amount of N(1),N(8)-bis(gamma-glutamyl)SPD were found. The significance of these results is discussed with respect to the activation of the protease by post-translational modification and design of potential inhibitors.

Lentini, A., Tabolacci, C., Melino, S.m., Provenzano, B., Beninati, S. (2010). Post-translational modification of glutamine and lysine residues of HIV-1 aspartyl protease by transglutaminase increases its catalytic activity. BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 393(3), 546-550 [10.1016/j.bbrc.2010.02.060].

Post-translational modification of glutamine and lysine residues of HIV-1 aspartyl protease by transglutaminase increases its catalytic activity

LENTINI, ALESSANDRO;MELINO, SONIA MICHAELA;PROVENZANO, BRUNO;BENINATI, SIMONE
2010-03-12

Abstract

The human immunodeficiency virus type 1 aspartyl protease (HIV-1 PR) is a homodimeric aspartyl endopeptidase that is required for virus replication. HIV-1 PR was shown to act invitro as acyl-donor and -acceptor for both guinea pig liver transglutaminase (TG, EC 2.3.2.13) and human Factor XIIIa. These preliminary evidences suggested that the HIV-1 PR contains at least three TG-reactive glutaminyl and one lysyl residues. We report here that the incubation of HIV-1 PR with TG increases its catalytic activity. This increase is dependent upon the time of incubation, the concentration of TG and the presence of Ca2+. Identification of epsilon-(gamma-glutamyl)lysine in the proteolytic digest of the TG-modified HIV-1 PR suggested intramolecular covalent cross-linking of this protease which may promote a non-covalent dimerization and subsequent activation of this enzyme via a conformational change. This hypothesis is supported by the observation that the TG-catalyzed activation of HIV-1 PR was completely abolished by spermidine (SPD) which acts as a competitive inhibitor of epsilon-(gamma-glutamyl)lysine formation. Indeed, in the presence of 1mM SPD the formation of the isopeptide was decreased of about 80%. The main products of the TG-catalyzed modification of HIV-1 PR in the presence of SPD were N(1)-mono(gamma-glutamyl)SPD and N(8)-mono(gamma-glutamyl)SPD. Negligible amount of N(1),N(8)-bis(gamma-glutamyl)SPD were found. The significance of these results is discussed with respect to the activation of the protease by post-translational modification and design of potential inhibitors.
12-mar-2010
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore BIO/10 - BIOCHIMICA
English
Con Impact Factor ISI
Factor XIIIa; Catalysis; Aspartic Acid Proteases; Glutamine; Protein Processing, Post-Translational; Animals; Lysine; Humans; Spermidine; Enzyme Activation; Transglutaminases; HIV-1; Liver; Guinea Pigs
Lentini, A., Tabolacci, C., Melino, S.m., Provenzano, B., Beninati, S. (2010). Post-translational modification of glutamine and lysine residues of HIV-1 aspartyl protease by transglutaminase increases its catalytic activity. BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 393(3), 546-550 [10.1016/j.bbrc.2010.02.060].
Lentini, A; Tabolacci, C; Melino, Sm; Provenzano, B; Beninati, S
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/13137
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