CHEMICAL MODIFICATION OF ESSENTIAL ARGININES IN PIG-LIVER PHOSPHOMEVALONATE KINASE

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dc.contributor.authorVERGARA, M
dc.contributor.authorALVEAR, M
dc.contributor.authorCARDEMIL, E
dc.contributor.authorJABALQUINTO, AM
dc.contributor.authorEYZAGUIRRE, J
dc.date.accessioned2025-01-23T19:44:11Z
dc.date.available2025-01-23T19:44:11Z
dc.date.issued1982
dc.description.abstractPhosphomevalonate [MVAP] kinase, an enzyme of the polyisoprenoid biosynthesis pathway, catalyzes the transfer of phosphate from ATP to MVAP, with the formation of pyrophosphomevalonate and ADP. The pig liver enzyme, a monomer of MW 22,000, possesses 1 cysteinyl residue, which is essential for catalysis. By means of chemical modification of a partially purified preparation, the participation of arginine residues in the enzyme active site was studied. Butanedione and phenylglyoxal were chosen as group-specific reagents. The kinetics of inactivation by both reagents is rather complex, suggesting that several arginine residues, directly or indirectly related to the active site, are being modified. Both substrates, MVAP and Mg-ATP, protect against inactivation but to a different extent, depending on the modifier used. With butanedione, almost total protection is achieved with Mg-ATP. Better protection with MVAP is observed for the modification with phenylglyoxal, but with this reagent, Mg-ATP protects strongly only at very high concentrations. A reversible inactivation mechanism is followed with butanedione, while for phenylglyoxal this mechanism appears to be irreversible, in agreement with findings by other authors. MVAP kinase probably presents 2 or more arginyl residues in or near its active site, one of them being involved in the binding of Mg-ATP, and at least another located in the neighborhood of the MVAP binding site. A more precise determination of the number of essential residues requires its measurement by chemical methods, utilizing a homogeneous enzyme preparation.
dc.fuente.origenWOS
dc.identifier.issn0004-0533
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/99971
dc.identifier.wosidWOS:A1982PY94500027
dc.issue.numero3-4
dc.language.isoen
dc.pagina.final430
dc.pagina.inicio423
dc.revistaArchivos de biologia y medicina experimentales
dc.rightsacceso restringido
dc.subject.ods03 Good Health and Well-being
dc.subject.odspa03 Salud y bienestar
dc.titleCHEMICAL MODIFICATION OF ESSENTIAL ARGININES IN PIG-LIVER PHOSPHOMEVALONATE KINASE
dc.typeartículo
dc.volumen15
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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