title: Cholesterol hemisuccinate: a selective inhibitor of family X DNA polymerases.
abstract: Cholesterol hemisuccinate (compound 5), which consists of succinic acid esterified to the beta-hydroxyl group of cholesterol, selectively and strongly inhibited the activities of mammalian DNA polymerases (pols) such as pol beta, pol lambda, and terminal deoxynucleotidyltransferase (TdT), which are family X pols, in vitro, and the IC50 values were 2.9, 6.3, and 6.5 microM, respectively. The compound moderately suppressed the activities of other mammalian pols such as pol A (i.e., pol gamma), pol B (i.e., pols alpha, delta, and epsilon), and pol Y (i.e., pols iota, eta, and kappa) with 50% inhibition observed at concentrations of 131, 89.2-98.0, and 120-125 microM, respectively. The compound had no influence on the activities of plant pols alpha and beta, prokaryotic pols and other DNA metabolic enzymes tested. Since other cholesterol-related compounds such as cholesterol, cholesteryl chloride, cholesteryl bromide, cholesteryl acetate, and cholesteryl-5alpha, 6alpha-epoxide (compounds 1-4 and 6, respectively) did not influence the activities of any enzymes tested, the hemisuccinate group of compound 5 could be important for inhibition of the pol X family. Surface plasmon resonance analysis demonstrated that compound 5 bound selectively to the C-terminal 31 kDa domain of pol beta and pol lambda containing a pol beta-like region. On the basis of these results, the inhibitory mechanism of compound 5 on the pol X family was discussed.
authors.affiliation: Laboratory of Food & Nutritional Sciences, Department of Nutritional Science, Kobe-Gakuin University, Kobe, Hyogo 651-2180, Japan.
authors.forename: Chisato
authors.initials: C
authors.lastname: Ishimaru
authors.forename: Isoko
authors.initials: I
authors.lastname: Kuriyama
authors.forename: Noriko
authors.initials: N
authors.lastname: Shimazaki
authors.forename: Osamu
authors.initials: O
authors.lastname: Koiwai
authors.forename: Kengo
authors.initials: K
authors.lastname: Sakaguchi
authors.forename: Ikuo
authors.initials: I
authors.lastname: Kato
authors.forename: Hiromi
authors.initials: H
authors.lastname: Yoshida
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Mizushina
mesh_terms: D000818:Animals; D001665:Binding Sites; D002788:Cholesterol Esters / Q000737:chemistry / Q000494:pharmacology*; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D029941:Fish Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry; D006801:Humans; D019476:Insect Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry; D005810:Multigene Family; D019384:Nucleic Acid Synthesis Inhibitors; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry
chemical_list: D002788:Cholesterol Esters; D004791:Enzyme Inhibitors; D029941:Fish Proteins; D019476:Insect Proteins; D019384:Nucleic Acid Synthesis Inhibitors; D010940:Plant Proteins; D004259:DNA-Directed DNA Polymerase; C013440:cholesteryl succinate