Cyclobutane thymine dimers, the major photoproducts produced in UV-irradiated DNA, are the main causative agents for mutagenesis and skin cancer. This lesion can also be initiated under UVA radiation, involving triplet–triplet energy transfer mechanism from a photosensitizer to the thymine nucleobase. According to previous reports, only photosensitizers with a triplet state energy >270 kJ mol 1...

It has been clearly established (1, 2), through the use of N16-labeled material, that the utilization of free thymine for the synthesis of deoxyribonucleic acid (DNA) by the rat is extremely limited. However, these studies afforded but little information concerning the rate and extent of the metabolism of thymine. In the experiments reported here, thymine-204 has been found to be more rapidly a...

Mutation can alter the structure of viral proteins to form different structure. Carbon distribution is responsible for these changes in structure. The carbon distribution in proteins of human Influenza A virus is analyzed here. Results reveal that the carbon contents are high in surface proteins, optimum in polymerase proteins and less in nuclear proteins. Polymerase proteins have better carbon...

Three types of experiments have been used to study the metabolism of thymine nucleotides by human cells. (1) Cells were labelled continuously with [3H]thymidine and the incorporation of label into DNA compared with the specific radioactivities of pools of individual thymine nucleotides separated by chromatography on polyethylene-imine-cellulose. (2) Cellular thymine nucleotides were labelled wi...

A linear UV dose response is demonstrated using an ELISA assay that measures thymine dimers formed in the genomic DNA extracted from mixed species of microorganisms filtered treated pre-disinfection drinking water.

A new DNA polymerase has been purified lOOO-fold from Bacillus subtilis infected with bacteriophage SPOl. It consists of a single polypeptide chain of approximately 122,000 molecular weight. The enzyme requires deoxyribonucleoside 5’-triphosphates, Mg2+, /3-mercaptoethanol, and single stranded DNA templates for activity. Bihelical DNA which has been partially denatured serves as the preferred t...

An American kindred with systemic amyloidosis presenting with carpal tunnel syndrome, peripheral neuropathy, and cardiomyopathy is reported. The transthyretin gene of a patient was analysed by direct DNA sequencing and both cytosine and thymine were present at the first base of codon 24. This new point mutation in exon 2 results in the amino acid substitution of serine for proline in the A-B lo...

Human polymerase kappa (polkappa), the product of the human POLK (DINB1) gene, is a member of the Y superfamily of DNA polymerases that support replicative bypass of chemically modified DNA bases (Ohmori, H., Friedberg, E. C., Fuchs, R. P., Goodman, M. F., Hanaoka, F., Hinkle, D., Kunkel, T. A., Lawrence, C. W., Livneh, Z., Nohmi, T., Prakash, L., Prakash, S., Todo, T., Walker, G. C., Wang, Z.,...

Using a first-principles linear response theory, the capacitance of the DNA nucleotides, adenine, cytosine, guanine, and thymine, are calculated. The difference in the capacitance between the nucleotides is studied with respect to conformational distortion. The result suggests that although an alternate current capacitance measurement of a single-stranded DNA chain threaded through a nanogap el...