Biochemistry international 

About: Biochemistry international is an academic journal. The journal publishes majorly in the area(s): Enzyme & Amino acid. It has an ISSN identifier of 0158-5231. Over the lifetime, 2338 publications have been published receiving 18358 citations.

Superoxide--driven oxidation of quercetin and a simple sensitive assay for determination of superoxide dismutase.

Abstract: Oxidation of quercetin at pH 10 was shown to be a free radical chain reaction involving superoxide and hence inhibitable by superoxide dismutase (SOD) (EC 11511) The degree of inhibition of quercetin oxidation was a function of SOD concentration, and fifty percent inhibition was produced by approximately 15 ng/ml of pure enzyme This reaction proved to be a very useful tool for a rapid and highly sensitive measurement of SOD in crude tissue extracts and other biological samples

Intracellular regulatory system involving calpain and calpastatin.

Abstract: Seven years have elapsed since the terms calpain and calpastatin were introduced. During these years, significant progress in research has been recorded. Thus, cloning and sequencing of cDNAs for calpains I and II and calpastatin have established amino acid sequences of these molecules. Structure-function relationship of calpastatin has been studied using mutated cDNAs expressed in E. coli. Interleukin 2 receptor-linked expression of calpastatin in HTLV-I-infected T-cells has been reported. Evidence for Ca2+-induced translocation of calpain to the cell membrane, followed by its autolytic activation, has been discussed. A great varieties of proteins such as several kinases, membrane and cytoskeletal proteins, and hormone receptors have been reported to be susceptible to calpains. This paper is to summarize our current knowledge on chemistry and biology of calpain and calpastatin and thereby to speculate the true function of calpains and their regulatory mechanisms.

Mitochondrial gene mutation: the ageing process and degenerative diseases.

Abstract: Polymerase chain reaction (PCR) amplification was carried out on total DNA from a range of autopsy tissues from deceased human subjects with no known mitochondrial disease, aged from birth (80 minutes) to 87 years. We report the finding of an age-related 5 kb deletion in the mitochondrial genomes of these subjects. The deletion occurs between nucleotide positions 8470 and 13459 of the mitochondrial genome, and is flanked by a 13 bp direct repeat. All tissues from adult subjects showed the presence of mitochondrial DNA molecules with the deletion after a 30 cycle PCR amplification; by contrast the deletion was not similarly detected in any of the infant tissues analysed. However, the occurrence of the deletion was detected in the infant tissues after 60 PCR cycles of MtDNA amplification. It is concluded that such deletions are not necessarily associated with particular mitochondrial diseases but occur naturally, and with increasing frequency with age. A consequence of the accumulation of this deletion could be a progressive decrease with age of bioenergetic capacity which in turn could influence the rate of ageing and predispose to age-associated degenerative diseases.

Protective effect of oleanolic acid and ursolic acid against lipid peroxidation.

Abstract: In a search for plant products against cancer, the protective effect of two plant products, ursolic acid isolated from Ocimum sanctum and oleanolic acid from Eugenia jumbolana against free radical induced damage was studied Three different standard systems viz, ascorbic acid, carbon tetrachloride, ADP/Iron were used to induce lipid peroxidation in isolated rat liver microsomes in vitro Both oleanolic acid and ursolic acid offered remarkable protection of 90% and 60% respectively Both the compounds did not induce lipid peroxidation by themselves that improved the therapeutic application

Validation of the MTT dye assay for enumeration of cells in proliferative and antiproliferative assays.

Abstract: Increasing use is being made of colorimetric assays to quantitate viable cells, e.g., the cellular reduction of the tetrazolium salt, MTT, to formazan by mitochondrial succinate dehydrogenase. We validated this assay for cell proliferation in mixed lymphocyte cultures as compared with 3H-thymidine uptake, and for inhibition of cell proliferation induced by interferon with results compared by direct cell counting. We also found that cells do not, as previously assumed, require functional mitochondria: there were no differences in formazan production by normal cells or respiratory defective cells in which mitochondria had been poisoned by the nucleic acid toxin, ethidium bromide. The high reproducibility of MTT metabolism by lymphoblasts and various cultured cell lines establishes the reliability and versatility of this method for quantitating cell numbers.