Sites of exendin-4 that that are relatively susceptible to degradation in plasma were identified with the aim of providing information for designing new exendin-4 analogues. The stability of exendin-4 in human plasma was evaluated in vitro. The results showed that the peptide was slowly degraded with a half-life of 9.57 h and the principal cleavage sites are between Thr5 and Phe6, Phe6 and Thr7, and Thr7 and Ser8 of the N-terminus region of exendin-4.
Protein & Peptide Letters publishes short papers in all important aspects of protein and peptide research, including structural studies, recombinant expression, function, synthesis, enzymology, immunology, molecular modeling, drug design etc. Manuscripts must have a significant element of novelty, timeliness and urgency that merit rapid publication. Reports of crystallisation, and preliminary structure determinations of biologically important proteins are acceptable. Purely theoretical papers are also acceptable provided they provide new insight into the principles of protein/peptide structure and function.