INSTRUMENTATION AND APPLICATIONS OF AN AUTOMATED C-TERMINAL FRAGMENT PEPTIDE FRACTIONATOR FOR C-TERMINAL SEQUENCE-ANALYSIS OF PROTEINS

A novel automated C-terminal fragment peptide fractionator has been co nstructed. Digests with lysyl endopeptidase were covalently immobilize d on p-phenylene diisothiocyanate polymer beads. Only the C-terminal f ragment, which contains no lysyl residue, was liberated by cleavage at the first peptide bond of the immobilized fragment peptides with trif luoroacetic acid, and it was automatically collected. The whole proced ure was automatically and precisely performed under microprocessor con trol in a nitrogen atmosphere, The resulting fragment was sequenced wi thout further purification. Sequences of both N- and C-terminal region s can be routinely obtained for ca. 100 pmol samples by the use of a c onventional automated Edman-type protein sequencer.