INVESTIGADORES
ISSOGLIO Federico Matias
artículos
Título:
Structural and biochemical insight into glycogenin inactivation by the glycogenosis-causing T82M mutation
Autor/es:
CARRIZO MARÍA E.; ROMERO, JORGE M.; ISSOGLIO, FEDERICO M.; CURTINO, JUAN A.
Revista:
FEBS LETTERS
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2012 vol. 586 p. 254 - 257
ISSN:
0014-5793
Resumen:
The X-ray structure of rabbit glycogenin containing the T82M (T83M according to previous authors amino acid numbering [1]) mutation causing glycogenosis showed the loss of Thr82 hydrogen bond to Asp162, the residue involved in the activation step of the glucose transfer reaction mechanism. Autoglucosylation, maltoside transglucosylation and UDP-glucose hydrolyzing activities were abolished even though affinity and interactions with UDP-glucose and positioning of Tyr194 acceptor were conserved. Substitution of Thr82 for serine but not for valine restored the maximum extent of autoglucosylation as well as transglucosylation and UDP-glucose hydrolysis rate. Results provided evidence sustaining the essential role of the lost single hydrogen bond for UDP-glucose activation leading to glycogenin-bound glycogen primer synthesis.