Molecular and chemical analysis of the protein subunits and fractions of sesame meal in comparison to cottonseed meal and soybean meal using SDS-Page electrophoresis and CNCPS methods

In this research, two methods including SDS-Page electrophoresis and CNCPS were used to study the protein subunits and fractions of sesame meal in comparison to cottonseed meal and soybean meal. The results of protein fractions according to CNCPS showed a significant difference (p<0.05) among non-protein nitrogen (A), rapidly degradable true protein (B1), moderately degradable true protein (B2), slowly degradable true protein (B3) and undegradable true protein (C) fractions of sesame meal in comparison to cottonseed meal and soybean meal. In regards to SDS-Page electrophoresis results, protein of sesame meal were mainly composed of 11S globulins and 2S albumins. Protein 11S globulins contained one acidic polypeptide with estimated MWs of 85.96 kDa and two basic polypeptides with estimated MWs of 17.04 -28.87 kDa. Furthermore, protein 2S albumins of sesame meal contained two subunits with estimated MWs of 9.5 to 10.51 kDa. The pattern of protein subunits in cottonseed meal shows four major polypeptides including globulin 9S (with MWs of 78.36 and 71.10 kDa), globulin 5S (with MW of 25.47 kDa) and albumin 2S (with MW of 15.84 kDa). In this research, two major polypeptides including β-Conglycinin (three subunits, α, ά, β with M Ws of 91.83, 80.49 and 47.16 respectively) and glycinin (two acidic and basic subunits with MWs of 40 and 21.30 kDa respectively) were observed in soybean meal. The results of the current study show that sesame meal has a good nutritive value and can be a good substitute for cottonseed meal in animal nutrition.