Protein & Peptide Letters publishes short papers in all important aspects of protein and peptide research, including structural studies, advances in recombinant expression, 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 crystallization and preliminary structure determination of biologically important proteins will be considered only if they include significant new approaches or deal with proteins of immediate importance, 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.