Pumpkin(Cucurbitasp.) seed globulin IV. Terminal sequences of the acidic and basic peptide chains and identification of a pyroglutamyl peptide chain

摘要

Pumpkin seed globulin is composed of heterogeneous polypeptide chains, acidicγandγ′chains and basicδ1andδ2chains(12). This study showed that the basic chains had similar N-terminal sequences, Gly-Leu-Asp-Glu-Thr-Ile- for theδ1chain and Gly-Leu-Glu-Glu-Thr-Ile- forδ2. On the contrary, the N-terminal sequences of the acidicγandγ′chains were dissimilar, Ile-Gln-Gly-Tyr- for theγchain and no N-terminal residue for theγ′chain, according to routine terminal analysis. Pyrrolidonyl peptidase digestion of theγ′chain and its thermolysin digestion followed by Edman degradations revealed that the N-terminal sequence of theγ′chain was