BIOCHEMICAL STUDIES ON BLACK GRAM (PHASEOLUS MUNGO): I. Solubilization and Electrophoretic Characterization of The Proteins.

Protein content of 60 mesh, dehydrated, defatted black gram (Phaseolus mungo) meal was 28.5%. Sodium carbonate (0.5–1.0%), te trasodium pyrophosphate (0.5%), and sodium dodecyl sulfate (0.5–5%) extracted more than 76 gram Lowry's protein per 100 gram Kjeldahl protein. On the considerations of contaminating residue in the final product and disruption of native structure of the proteins these chemical agents were unsuitable. Sodium sulfate at 10% level was judged to be the best protein solubilizer. The phenol-acetic acid-mercaptoethanol-urea (PAMU) system in polyacrylamide gel electrophoresis was more efficient in resolving protein subunits than the sodium dodecyl sulfate (SDS) gel system. PAMU dissociated total black gram proteins in one major and 7–8 other sharp bands. Proteins separated on PAMU gel were run on the flat bed polyacrylamide gel containing SDS system. The proteins were then separated in 13 subunits, the molecular weight of the major one was 55,000. Defatting with n-hexane improved protein extraction by 6%. Solubilized proteins contained 81% globulins, 13% albumins, 4% ethanol soluble proteins, and 2% acetic acid soluble proteins.