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Biomedical subjects

V K Mohan Rao

Publications and source records attributed to V K Mohan Rao.

7 recordsLinked to original sources
PubMed1978

L-Histidine ammonia-lyase activity of axenically grown Hartmannella culbertsoni.

1. Histidine ammonia-lyase (EC 4.3.1.3) activity in the cell-free extracts of Hartmannella culbertsoni has been partially purified and the optimum activity is found at pH 9.0--9.2. 2. The enzyme required sulphydryl groups for its activity. L-2-Thiohistidine and EDTA competitively inhibit the enzyme. 3. Its molecular weight, as determined by gel filtration technique, is 131,800 daltons and the energy of activation for this enzyme is 15,205 cals/mole. 4. Certain amoebicidal drug and divalent cations have marked inhibitory effect on the enzyme. Co2+ has a profound stimulatory effect.

Amebicides↗
PubMed1975

Ribonuclease activity of Entamoeba histolytica.

Ribonuclease activity of Entamoeba histolytica was purified 65-fold by calcium phosphate gel, ammonium sulphate and acetone treatments. The enzyme was inhibited by metal ions, like Mg-2+, Mn-2+, Co-2+ and Ca-2+. Metal chelating and sulphydryl agents showed no effect. EDTA and alpha, a'-dipyridyl reversed the inhibition produced by Mg-2+, Mn-2+ and Fe-2+. Various sodium salts had negligible effect on the enzyme; however, sodium chloride activated the enzyme slightly. Amoebicidal drugs like enterovioform and chloroquine phosphate inhibited the enzyme completely, while emetine showed marked inhibitory effect. Neomycin exhibited a slight stimulatory action on this enzyme.

Amebicides↗
PubMedDate not supplied

In vitro conversion of proinsulin to insulin by cathepsin B and role of C-peptide.

Cathepsin B, purified from isolated islets of Langerhans, when incubated with proinsulin under in vitro conditions could convert proinsulin to insulin and C-peptide, releasing free arginine and lysine. When C-peptide, prepared from rat pancreas, was added to the incubation system consisting of proinsulin and cathepsin B, it completely inhibited the conversion of proinsulin to insulin.

Animals↗