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Biomedical subjects

R Venkatakrishnan

Publications and source records attributed to R Venkatakrishnan.

5 recordsLinked to original sources
PubMed1979

The structure, function, and turnover of cardiac myosin in normal and myopathic Syrian hamsters.

Cardiac myosin was examined during the four pathologic stages of cardiomyopathy in strain BIO 14.6 of Syrian hamsters. It was determined that the Ca2+- and K+-ethylenediaminetetraacetic acid (EDTA)-activated ATPase activities of ventricular myosin were significantly reduced during the final stage of the inherited disease. One- and 2-dimensional gel electrophoresis of myosin samples at all stages failed to yield any evidence for a change in the subunit structure of myosin based on light chain number, molecular weight, and per cent composition. The final stage of the disease was characterized by altered protein metabolism. The rates of synthesis and degradation were both altered in the diseased tissue, and a net loss of myosin resulting from a substantial increase in the rate of degradation.

Adenosine Triphosphatases↗
PubMed1976

Homologous inhibitors from potato tubers of serine endopeptidases and metallocarboxypeptidases.

A potent polypeptide inhibitor of chymotrypsin has been purified from Russett Burbank potatoes. The inhibitor has no effect on bovine carboxypeptidases A or B but exhibits homology with a carboxypeptidase inhibitor that is also present in potato tubers. The chymotrypsin inhibitor has a molecular weight of approximately 5400 as estimated by gel filtration, amino acid analysis, and titration with chymotrypsin. The polypeptide chain consists of 49 amino acid residues, of which six are half-cystine, forming three disulfide bonds. Its size is similar to that of the carboxypeptidase inhibitor, which contains 39 amino acid residues and also has three disulfide bridges. In immunological double diffusion assays, the chymotrypsin inhibitor and the carboxypeptidase inhibitor do not crossreact; however, automatic Edman degradation of reduced and alkylated derivatives of the chymotrypsin inhibitor, yielding a partial sequence of 18 amino acid residues at the NH2-terminus, reveals a similarity in sequence to that of the carboxypeptidase inhibitor. Thus, inhibitors directed toward two distinct classes of proteases, the serine endopeptidases and the metallocarboxypeptidases, appear to have evolved from a common ancestor.

Amino Acid Sequence↗