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Biomedical subjects

R J Pennington

Publications and source records attributed to R J Pennington.

At least 55 records · Page 3Linked to original sources
PubMed1971

Studies on proteolytic activity in commercial myoglobin preparations.

Commercial myoglobin preparations from horse skeletal muscle degraded casein. The maximum activity was at pH8-8.5. A muscle myofibril preparation was also attacked. The protease could be partly separated from the myoglobin by selective ultrafiltration through a membrane with an exclusion limit of mol.wt. 30000. A greater than 1000-fold purification of the proteolytic activity was achieved by affinity chromatography with soya-bean trypsin inhibitor bound to CM-cellulose. The enzyme preparation hydrolysed p-toluenesulphonyl-l-arginine methyl ester and N-benzyloxycarbonyl-l-tyrosine p-nitrophenyl ester. Its activity was inhibited strongly by soya-bean and ovomucoid trypsin inhibitors, serum and the soluble fraction of muscle homogenates. EDTA, p-chloromercuribenzoate and phenylmethylsulphonyl fluoride also caused some inhibition.

Arginine↗
PubMed1970

A ribonuclease from human skeletal muscle.

1. A ribonuclease has been prepared from human muscle by ammonium sulphate fractionation, heat treatment and ion-exchange chromatography. 2. The enzyme degrades polycytidylic acid and polyuridylic acid to the nucleoside 3'-phosphates, with nucleoside 2':3'-cyclic phosphates as intermediates. Polyadenylic acid and polyguanylic acid are not attacked. 3. The enzyme has maximal activity at pH8.5. The molecular weight (by gel filtration) is between 11000 and 12000. It is relatively heat-stable. It exhibits optimum activity in a medium of high ionic strength, and is inhibited by several bivalent cations, particularly Zn(2+).

Chemical Precipitation↗