Human beta crystallins: regional and age related changes.
The composition of human beta-crystallins displayed specific changes with age and region of the lens. 27 kD and 29 kD human beta-crystallin subunits were singled out for study. The 29 kD beta-crystallin subunit constituted approximately 10% of the total lens crystallins at 8 months of fetal life. Its accumulation decreased steadily to 3.3% during postnatal year 1, to 0.5% by year 5 and to 0.3% thereafter. At all postnatal ages, however, it persisted mainly in the superficial fibers. Thus in a 17-years old lens it made up 1.3% of the superficial fiber soluble protein but was already absent from deep cortical and nuclear fibers. The 27 kD subunit increased steadily from 3.5% at 8 months fetal to 7% at year 5; it then decreased steadily to 1.2% in the 86-year old lens. It persisted in all regions of the lens but decreased markedly in the deep cortical and nuclear fibers with increasing age beginning at 5-17 years of age. Studies on the oligomeric structure of human beta-crystallin must take into account age-related changing quantitative patterns in the subunit polypeptide composition of this lens protein.
Alcala
J
J
Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201.
Katar
M
M
Rudner
G
G
Maisel
H
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D002850:Chromatography, Gel; D003459:Crystallins / Q000145:classification* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005333:Fetus; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007908:Lens, Crystalline / Q000378:metabolism*; D008875:Middle Aged; D008970:Molecular Weight; D014018:Tissue Distribution
D003459:Crystallins