Cleavage Specificity
No specific amino acid sequence is uniquely recognized by calpains. Amongst protein substrates, tertiary structure elements rather than primary amino acid sequences are likely responsible for directing cleavage to a specific substrate. Amongst peptide and small-molecule substrates, the most consistently reported specificity is for small, hydrophobic amino acids (e.g. leucine, valine and isoleucine) at the P2 position, and large hydrophobic amino acids (e.g. phenylalanine and tyrosine) at the P1 position. Arguably, the best currently available fluorogenic calpain substrate is (EDANS)-Glu-Pro-Leu-Phe=Ala-Glu-Arg-Lys-(DABCYL), with cleavage occurring at the Phe=Ala bond.
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Famous quotes containing the word cleavage:
“Jesus abolished the very concept of “guilt”Mhe denied any cleavage between God and man. He lived this unity of God and man as his “glad tidings” ... and not as a prerogative!”
—Friedrich Nietzsche (1844–1900)