Identification of epsilon-crystallin from swan lens as lactate dehydrogenase.
Characterization of lens crystallins from black swan, a rare aquatic bird belonging to the family Anatidae, was carried out to search for epsilon-crystallin with lactate dehydrogenase activity. Biochemical comparison of epsilon-crystallins isolated from the swan and duck lenses plus lactate dehydrogenase of chicken heart has also been made in order to establish the structural/functional relatedness of these proteins. Amino acid analyses showed essentially similar overall compositions for these three proteins. Kinetic analysis revealed differences between avian epsilon-crystallins and the authentic heart-type lactate dehydrogenase. The swan lenses similar to duck lenses appeared to contain a thermostable epsilon-crystallin which possesses very high enzymatic activity of lactate dehydrogenase. The characterization of epsilon-crystallins from the available species of aquatic birds may provide some insights into the evolution of this unique crystallin in the Aves and their enzymatic roles inside the lens.
Chiou
S H
SH
Laboratory of Crystallin Research, National Taiwan University, Taipei.
Chang
W P
WP
Lai
T A
TA
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001717:Birds; D002645:Chickens; D002852:Chromatography, Ion Exchange; D003459:Crystallins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D004372:Ducks; D004591:Electrophoresis, Polyacrylamide Gel; D005779:Immunodiffusion; D007525:Isoelectric Focusing; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D007908:Lens, Crystalline / Q000201:enzymology*; D009206:Myocardium / Q000201:enzymology; D013552:Swine
D000596:Amino Acids; D003459:Crystallins; D007770:L-Lactate Dehydrogenase