title: Inhibition of DNA polymerase activity by methyl methanesulfonate.
abstract: Methyl methanesulfonate (MMS) inhibits both thymidine incorporation into DNA in mitogen-activated human lymphocytes and deoxythymidine triphosphate incorporation into template DNA by DNA polymerase-alpha in a cell-free system. When MMS-modified DNA was used as the template for DNA synthesis utilizing unmodified DNA polymerase-alpha, nucleotide incorporation into template DNA was not inhibited. When unmodified DNA was used as the template for DNA synthesis utilizing MMS-modified DNA polymerase-alpha, nucleotide incorporation was differentially inhibited dependent on the MMS concentration. An analysis of the kinetics of DNA polymerase-alpha inhibition showed that incorporation of all 4 deoxynucleoside triphosphates into DNA template was noncompetitively inhibited by MMS, which is consistent with nonspecific MMS modification of the enzyme. These data indicate that MMS modification of DNA polymerase-alpha alone is sufficient to inhibit the incorporation of deoxynucleoside triphosphates into template DNA in vitro. The data further indicate that alkylation of both DNA polymerase-alpha and DNA template synergistically increases inhibition of DNA synthesis.
mesh_terms: D000478:Alkylation; D000818:Animals; D002474:Cell-Free System; D004257:DNA Polymerase II / Q000037:antagonists & inhibitors*; D004261:DNA Replication / Q000187:drug effects*; D008214:Lymphocytes; D008741:Methyl Methanesulfonate / Q000494:pharmacology*; D051379:Mice; D013698:Templates, Genetic
chemical_list: D008741:Methyl Methanesulfonate; D004257:DNA Polymerase II