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Biomedical subjects

A Matsukage

Publications and source records attributed to A Matsukage.

At least 145 records · Page 8Linked to original sources
PubMed1980

In vitro synthesis of short DNA pieces by DNA polymerase alpha from mouse myeloma.

The DNA chain elongation mechanisms of mouse DNA polymerases alpha and beta have been analyzed by using denatured DNA with a (dT)n block at the 3'-end as a template in combination with RNA ((rA)12-20)primer. The (rA)12-20-primed DNA product synthesized by DNA polymerase alpha was 3-5 s in size even after prolonged reaction; instead of a size increase, the number of 3-5 s molecules increased with the reaction time. The size of products was not affected by differences in 3H-labeled substrate (dATP or dTTP), enzyme amount, KCl concentration, or the length of 3'-(dT)n blocks. On the other hand, DNA polymerase beta synthesized long DNA products by a highly distributive reaction mechanism. 3-5 sDNA pieces synthesized by DNA polymerase alpha were not elongated any further by DNA polymerase alpha, but were converted into long DNA chains by DNA polymerase beta. The results imply that DNA polymerase alpha recognizes the size of the product DNA, and shuts off further elongation.

Animals↗
PubMed1980

Steady-state kinetics of mouse DNA polymerase alpha.

Steady-state kinetic studies of DNA polymerase alpha purified from mouse myeloma MOPC104E cells have been carried out. The results of initial velocity analysis with or without sodium pyrophosphate, a product inhibitor, indicated that the reaction mechanism of this enzyme can be categorized as an ordered Bi Bi type where the concentration of the ternary complex is very low.

Animals↗
PubMed1980

Inhibition of terminal deoxynucleotidyltransferase by various diadenosine polyphosphates.

Terminal deoxynucleotidyltransferase (TdT) was found to be strongly inhibited by diadenosine 5',5"'-P1,P4-tetraphosphate (AP4A) while other mammalian DNA polymerases alpha, beta and gamma were neither inhibited nor activated by AP4A. Such inhibitory effect on TdT was also observed with a variety of diadenosine polyphosphates (APnA), n = 3-6) when TdT activity was assayed by determining incorporation of dCTP. Kinetic analysis revealed that the inhibition of TdT by APnA was due to competition with substrate deoxynucleoside triphosphate(s).

Adenine Nucleotides↗
PubMed1980

Characterization of two DNA polymerases from cauliflower inflorescence.

Two distinct DNA polymerases, A and B, isolated from a rapidly growing apical tissue of cauliflower (Brassica oleracea var. botrytis) inflorescence have been characterized, and compared with DNA polymerases, alpha and beta, from mouse myeloma. Polymerase-A bears a strong resemblance to polymerase-alpha from mammalian cells in all properties examined. The character of polymerase-B is also quite similar to polymerase-beta of mammalian cells in chromatographic elution properties, template-primer utilization, sensitivity to inhibitors, response to KCl or KPi concentration, and other requirements for maximal activity, although it has a higher molecular weight (approx. 78,000) even in the presence of 0.25 M KCl that polymerase-beta (mol. wt. less than or equal to 50,000) of mammalian cells. This type of DNA polymerase has not been reported to exist in the plant system.

Animals↗
PubMed1979

Unique requirements for template primers of DNA polymerase beta from rat ascites hepatoma AH130 cells.

The optimal condition for the rat DNA polymerase beta activity with (rA)n . (dT)12-18 as a template-primer was determined. The activity was remarkably affected by the concentration of the primer, (dT)12-18' and the mixing ratio of (dT)12-18 to (rA)n. DNA polymerase beta requires higher primer concentration (Km = 11.1 microM with respect to 3'-OH of the primer) than DNA polymerase gamma (Km = 0.04 microM) or oncornaviral DNA polymerase (Km = 0.08 microM) and the enzyme represented the maximum activity in the base ratio of 2:1 with (dT)12-18 and (rA)n suggesting the difference in reaction mechanisms of these enzymes. Under the optimized conditions, the specific activity of the near homogeneous preparation of DNA polymerase beta was 1,000,000 units per mg protein.

Animals↗
PubMed1979

Difference in the mechanisms of poly(dT) synthesis by DNA polymerases beta and gamma.

Poly(dT) products which were synthesized depending on (rA)n . (dT)12-18 as a template . primer by mammalian DNA polymerases beta and gamma were analyzed by alkaline sucrose gradient centrifugation. The size of the population of poly(dT) chains synthesized by DNA polymerase beta increased slowly and consistently during incubation up to at least 30 min. On the other hand, the product size with DNA polymerase gamma reached the final size (7 s) within 5 min and the number of products increased during further incubation. Comparison of product number per enzyme molecule suggests that DNA polymerase beta acts on multiple primers in a distributive fashion while DNA polymerase gamma completes poly(dT) chains of large size in a one-by-one fashion.

DNA Polymerase II↗
PubMed1979

Inhibitory effects of 9-beta-D-arabinofuranosylguanine 5'-triphosphate and 9-beta-D-arabinofuranosyladenine 5'-triphosphate on DNA polymerases from murine cells and oncornavirus.

The effects of the newly synthesized compound 9-beta-D-arabinofuranosylguanine 5'-triphosphate (ara-GTP) on the activity of DNA polymerases from mouse cells and oncornavirus were compared with those of 9-beta-D-arabinofuranosyladenine 5'-triphosphate. Ara-GTP did not replace deoxyguanosine 5'- triphosphate as substrate for these DNA polymerases but inhibited the activities of DNA polymerase alpha, beta, and gamma and viral DNA polymerase. DNA polymerase alpha was more sensitive than DNA polymerases beta and gamma and viral DNA polymerase to inhibition by ara-GTP. The inhibitions by ara-GTP and 9-beta-D-arabinofuranosyladenine 5'-triphosphate were due to competition or partial competition 5'-triphosphate were due to competition or partial competition with deoxynucleoside triphosphate with the same base. The inhibition constant (Ki) and the mode of inhibition of nucleotide incorporation varied depending on the combination of inhibitor, substrate(s), and enzyme species.

Animals↗
PubMed1979

Recognition of structure of 5-halogenated derivatives of ara-UTP by DNA polymerase gamma and reverse transcriptase.

This report deals with the test of a series of 5-halogenated derivatives of ara-UTP for the inhibition of DNA polymerase gamma and viral reverse transcriptase. The compounds newly synthesized and tested were; ara5-FUTP, ara5-C1UTP, ara5-BrUTP and ara5-IUTP. The results were: 1) All these compounds were inhibitory to DNA polymerase gamma and reverse transcriptase. The mode of inhibitions was, in all cases, competitive against dTTP. 2) Ki values for these inhibitors with DNA polymerase gamma were lower than those with reverse transcriptase. 3) Ara5-ClUTP was less inhibitory to reverse transcriptase than other derivatives.

Animals↗
PubMed1978

Inhibitory effect of 1-beta-D-arabinofuranosylthymine 5'-triphosphate and 1-beta-D-arabinofuranosylcytosine 5'-triphosphate on DNA polymerases from murine cells and oncornavirus.

This report compares the effect of the newly synthesized 1-beta-D-arabinofuranosylthymine 5'-triphosphate with 1-beta-D-arabinofuranosylcytosine 5'-triphosphate on the activity of DNA polymerases from mouse cells and oncornavirus. 1-beta-D-Arabinofuranosylthymine 5'-triphosphate inhibited all the activities of DNA polymerase alpha, beta, and gamma and viral DNA polymerase. The mode of inhibition of 1-beta-D-arabinofuranosylthymine 5'-triphosphate as well as 1-beta-D-arabinofuranosylcytosine 5'-triphosphate was competitive to the deoxynucleoside triphosphate with the same base. The inhibition constant (Ki) and the mode of inhibition of nucleotide incorporation varied with changes in the combination of the inhibitor, substrate(s), and enzyme species.

Animals↗
PubMed1977

Polynucleotide recognition by DNA alpha-polymerase.

In a survey of template-primer preference of a mouse myeloma DNA alpha-polymerase, the fastest rate of DNA synthesis was with poly(dT) as template and (rA)24 as primer. Such a preference for poly(dT).oligo(rA) was not observed with other DNA polymerases of mouse origin. DNA synthesis in this system resulted in formation of oligo(dA) chains, not template-length poly(dA); thus, the average enzyme molecule bound to a poly(dT).(rA)24 complex and initiated a new oligo(dA) chain many times during the incubation. Binding experiments revealed that the alpha-polymerase had high affinity for poly(dT). Although the alpha-polymerase did not bind to poly(dl) and failed to replicate it inreactions with a base pair complementary primer, poly(dl) was replicated after a (dT) block had been grafted to its 3'-end and the oligo(rA) primer had been added. In similar experiments, the (dT) block was found to be much more effective than other 3'-terminal blocks in promoting replication of denatured calf thymus DNA. The results indicate that specific base sequences may regulate initiation of DNA syntehsis by this alpha-polymerase.

Cell Line↗