Spontaneous cleavage of proteins at serine residues
Long-lived proteins are found at several sites in the body and they undergo numerous changes as a result of prolonged exposure to physiological conditions. Truncation is a common modification and many cleavages appear to be non-enzymatic, however little is known about the processes involved. In this study we demonstrate, using synthetic peptides that incorporate the sequence of a protein that is known to cleave in older lenses, that truncation on the N-terminal side of serine residues can occur at neutral pH. A mechanism that incorporates an N,O-acyl shift, which is analogous to intein cleavage, is proposed. Such cleavages may explain the origin of abundant peptides derived from crystallins in aged human lenses.
Please refer to publisher version or contact your library.