Protein distribution patterns in concentric layers from single bovine lenses: changes with development and ageing.
Protein distribution patterns were determined in concentric layers removed from 24 bovine lenses ranging in age from about 6 months before birth to 180 months post-natal. It was possible to distinguish alterations in protein synthesis patterns during development and changes due to ageing, i.e., prolonged existence of the proteins. It was found that alpha-crystallin represents a constant 50% of the proteins synthesized by the fibre cells throughout life. However, the protein becomes progressively less soluble with increasing age. Beta-crystallin synthesis increases from 30% of the total proteins during prenatal development to around 40% in post-natal fibre cells. This increase is due to increased production of the beta-crystallin. In old tissues, beta H-crystallin is converted to a high molecular weight from (HMW beta) gamma-crystallins account for 22% of the proteins synthesized in the earliest prenatal fibre cells. This level decreases rapidly through prenatal development until they represent about 4% of the total at birth. Beta S-crystallin synthesis commences around this time and in the post-natal fibre cells is essentially the only low molecular weight protein. The possible significance of some of these changes is discussed with regard to the functional requirements of the lens.
Pierscionek
B
B
Russell Grimwade School of Biochemistry, University of Melbourne, Parkville, Victoria, Australia.
Augusteyn
R C
RC
D000375:Aging / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D003459:Crystallins / Q000378:metabolism* / Q000502:physiology; D007908:Lens, Crystalline / Q000378:metabolism* / Q000502:physiology; D008970:Molecular Weight
D003459:Crystallins