A simple biomimetic mercury(II)-gated single nanochannel has been developed by incorporating a mercury(II) responsive single stranded DNA (ssDNA) with thymine-thymine (T-T) bases into a single polymetic nanochannel.

Addition of amethopterin to an incubation medium containing slices of the human tumor transplants H.S. #1 and II.Ep. #3 decreased selectively the utilization of orotie acid-C 1~ for the synthesis of DNA thymine. A substantially larger depression of the specific activity of DNA thymine was observed upon addition of both amethopterin and 5-bromouridine to the incubation medium than upon addition ...

Hydroxyl radical-induced formation of a DNA-protein cross-link involving thymine and lysine in calf thymus nucleohistone in vitro is reported. Basic amino acids such as lysine constitute a very high proportion of the amino acids of histones, and help histones to bind to DNA in chromatin. For this reason, basic amino acids are likely to participate in DNA-protein cross-linking. For identificatio...

The photodimerization reaction between the two adjacent thymine bases within a single strand has been the subject of numerous studies due to its potential to induce DNA mutagenesis and possible tumorigenesis in human skin cells. It is well established that the cycloaddition photoreaction takes place on a picosecond time scale along barrierless or low barrier singlet/triplet pathways. However, t...

The biochemistry of vitamin Biz has been the subject of several recent reviews (1, 2, 3). Evidence currently available indicates that the vitamin is required for the reduction of formate to methionine and choline methyl. Indirect evidence implicates vitamin Biz in thymine biosynthesis. Thymine will replace the Blz requirements in certain microorganisms (3) and will induce a reticulocyte respons...

We have examined the reactivity of B DNA with two chemical probes of DNA structure, potassium permanganate (KMnO4; thymine specific) and diethyl pyrocarbonate (DEPC; purine specific, A greater than G). The DNA probed is from the beta-lactamase promoter region of the vector pBR322, and from the 3' noncoding region of a chicken embryonic myosin heavy chain gene. The chemical probes display variab...

The disposition and metabolic fate of 3'-deoxy-2',3'-didehydrothymidine (D4T) were evaluated both in isolated hepatocytes and in nonhuman primates. Rapid formation of thymine and beta-aminoisobutyric acid (BAIBA) occurred following incubation of hepatocytes with 10 microM [5(-3)H]D4T. Substantial levels of tritiated water were also detected. Exposure of cells to D4T in the presence of either 1 ...