Identification of the in vivo truncation sites at the C-terminal region of alpha-A crystallin from aged bovine and human lens.
Total alpha-A crystallin was purified from young versus old lens, followed by digestion with cyanogen bromide. Laser desorption mass spectrometry of the C-terminal fragment demonstrated age-dependent loss of one and five amino acids from the C-terminus of alpha-A crystallin from both bovine and human lens. These results demonstrate specific peptide bonds of alpha-A crystallin are cleaved during the aging process of the normal lens. The C-terminal region is cleaved in two places between the two hydroxyl-containing amino acids present in the sequence -P-S(T)-S-.
Division of Biology, Kansas State University, Manhattan 66506, USA.
L J
LJ
Takemoto
D000818:Animals; D002417:Cattle; D003459:Crystallins / Q000737:chemistry / Q000302:isolation & purification*; D006801:Humans; D007908:Lens, Crystalline / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry
D003459:Crystallins; D010446:Peptide Fragments