Site-directed Mutagenesis of Key Residues Unveiled a Novel Allosteric Site on Human Adenosine Kinase for Pyrrolobenzoxa(thia)zepinone Non-Nucleoside Inhibitors.
Chem Biol Drug Des
; 87(1): 112-20, 2016 Jan.
Article
em En
| MEDLINE
| ID: mdl-26242695
ABSTRACT
Most nucleoside kinases, besides the catalytic domain, feature an allosteric domain which modulates their activity. Generally, non-substrate analogs, interacting with allosteric sites, represent a major opportunity for developing more selective and safer therapeutics. We recently developed a series of non-nucleoside non-competitive inhibitors of human adenosine kinase (hAK), based on a pyrrolobenzoxa(thia)zepinone scaffold. Based on computational analysis, we hypothesized the existence of a novel allosteric site on hAK, topographically distinct from the catalytic site. In this study, we have adopted a multidisciplinary approach including molecular modeling, biochemical studies, and site-directed mutagenesis to validate our hypothesis. Based on a three-dimensional model of interaction between hAK and our molecules, we designed, cloned, and expressed specific, single and double point mutants of hAK (Q74A, Q78A, H107A, K341A, F338A, and Q74A-F338A). Kinetic characterization of recombinant enzymes indicated that these mutations did not affect enzyme functioning; conversely, mutated enzymes are endowed of reduced susceptibility to our non-nucleoside inhibitors, while maintaining comparable affinity for nucleoside inhibitors to the wild-type enzyme. This study represents the first characterization and validation of a novel allosteric site in hAK and may pave the way to the development of novel selective and potent non-nucleoside inhibitors of hAK endowed with therapeutic potential.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Azepinas
/
Adenosina Quinase
/
Nucleosídeos
Limite:
Humans
Idioma:
En
Revista:
Chem Biol Drug Des
Assunto da revista:
BIOQUIMICA
/
FARMACIA
/
FARMACOLOGIA
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Itália