The electrophoresis of sodium dodecyl sulphate-polyacrylamide gel (SDS-PAGE) was carried out using the method of Laemmli [36], on a 5% polyacrylamide stacking gel and a 12% polyacrylamide-resolving gel. The protein marker ranging from 14.3 to 94.7 kDa was used as a standard marker for determination of molecular weight.Protein bands were visualized by silver staining