Strong-cation-exchange sulfoethyl aspartamide chromatography for peptide mapping of Staphylococcus aureus V8 protein digests

摘要: In two recent reports (D. L. Crimmins, J. Gorka, R. S. Thoma, and B. D. Schwartz (1988) Chromatogr. 443, 63-71; A. Alpert P. C. Andrews 85-96) a sulfoethyl aspartamide column was shown to efficiently analyze peptides less than 25 residues in length which differ the number of nominal positive charges at pH 3.0. particular, elution order for series distinct ranging charge from +1 +7 found be monotonic nature indicating that separation primarily via cation-exchange mechanism. The present study employs this chromatographic system isolate characterize major fragments proteolytic digests. Six commercially available proteins known sequence (myoglobin, beta-casein, concanavalin A, carbonic anhydrase, lentil lectin, enolase) were digested with Staphylococcus aureus V8 generate peptide fragments. resulting mixture chromatographed on then subjected amino acid analysis N-terminal sequencing. With complete proteolysis (i.e., terminating either an aspartic or glutamic acid) should result sum histidine, lysine, arginine contained each fragment. Most eluted expected time column. Those anomalous behavior resulted incomplete cleavage nonacidic greater 35 length. Each digest also analyzed by standard reverse-phase C4 chromatography compare maps these modes.