title: Photoreactive analogues of prenyl diphosphates as inhibitors and probes of human protein farnesyltransferase and geranylgeranyltransferase type I.
abstract: Photoreactive analogues of prenyl diphosphates have been useful in studying prenyltransferases. The effectiveness of analogues with different chain lengths as probes of recombinant human protein prenyltransferases is established here. A putative geranylgeranyl diphosphate analogue, 2-diazo-3,3,3-trifluoropropionyloxy-farnesyl diphosphate (DATFP-FPP), was the best inhibitor of both protein farnesyltransferase (PFT) and protein geranylgeranyltransferase-I (PFFT-I). Shorter photoreactive isprenyl diphosphate analogues with geranyl and dimethylallyl moieties and the DATFP-derivative of farnesyl monophosphate were much poorer inhibitors. DATFP-FPP was a competitive inhibitor of both PFT and PGGT-I with Ki values of 100 and 18 nM, respectively. [32P]DATFP-FPP specifically photoradiolabelled the beta-subunits of both PFT and PGGT-I. Photoradiolabelling of PGGT-I was inhibited more effectively by geranylgeranyl diphosphate than farnesyl diphosphate, whereas photoradiolabelling of PFT was inhibited better by farnesyl diphosphate than geranylgeranyl diphosphate. These results lead to the conclusions that DATFP-FPP is an effective probe of the prenyl diphosphate binding domains of PFT and PGGT-I. Furthermore, the beta-subunits of protein prenyltransferases must contribute significantly to the recognition and binding of the isoprenoid substrate.
authors.affiliation: Department of Biochemistry and Molecular Biology, J. Hillis Miller Health Center, University of Florida, Gainesville 32610, USA.
authors.forename: Y E
authors.initials: YE
authors.lastname: Bukhtiyarov
authors.forename: C A
authors.initials: CA
authors.lastname: Omer
authors.forename: C M
authors.initials: CM
authors.lastname: Allen
mesh_terms: D000345:Affinity Labels / Q000494:pharmacology*; D019883:Alkyl and Aryl Transferases; D003979:Diazonium Compounds / Q000494:pharmacology*; D006801:Humans; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors; D014166:Transferases / Q000037:antagonists & inhibitors*
chemical_list: C095155:2-diazo-3,3,3-trifluoropropionyloxy-farnesyl diphosphate; D000345:Affinity Labels; D003979:Diazonium Compounds; D011994:Recombinant Proteins; D014166:Transferases; D019883:Alkyl and Aryl Transferases; C083291:geranylgeranyltransferase type-I; C064911:p21(ras) farnesyl-protein transferase