Peptide mapping in sodium dodecyl sulfate-containing buffers: control of proteolytic cleavage by organic solvent.

Dimethylformamide (DMF) was found to enhance proteolysis in sodium dodecyl sulfate (SDS)-containing buffers. This effect was seen with both denatured and reduced proteins, which are insoluble in the absence of SDS, and with native proteins. The use of DMF and SDS to control proteolysis and solubility of proteins will be useful in amino acid sequence studies.