[Optimization of the method of cyanogen bromide mapping of polypeptides separated by polyacrylamide gel...

Two highly efficient methods of CNBr-peptide mapping of polypeptides divided by polyacrylamide gel electrophoresis are described. The first is elaborated on the basis of peptide mapping of collagen proposed by G. Barsh et al. The following three modifications diminish wasting the material essential for the method. 1. CNBr treatment takes place in the absence of CNBr solution outside the gel, excluding the peptides elution from the gel fragments in the process of mapping. 2. After CNBr treatment the solution of CNBr is substituted by the samples buffer before electrophoresis by means of drying and subsequent addition of minimal volumes of the buffer. The latter procedures substitute the gel washing out by the buffer solution. 3. The step of washing the gel fragments by the 70% strong solution of formic acid before CNBr treatment is excluded. The second method of CNBr-peptide mapping is notable for extracting peptides from the gel fragments in the process of CNBr-treatment and permits obtaining of the high quality peptide electrophoregrams.