Temperature and Guanidine hydrochloride induced unfolding transitions of papain at pH 2.0 are biphasic implying independent and sequential unfolding of its two domains. To determine the order of unfolding, the active site located in the interface of the domains was labeled with an environment specific fluorescent probe (1,8-IAEDANS). Unfolding of this complex relative to the free protein followed by intrinsic and extrinsic fluorescence measurements suggests that the N domain unfolds initially in the sequential unfolding of domains
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.