Characteristics of alpha-crystallin in human senile cataract

• Published in: Experimental eye research Vol. 16; no. 2; pp. 123 - 129
• Main Authors: Maraini, G., Mangili, R.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.1973
• Subjects: Aged; Amino Acids - analysis; Cataract - metabolism; Crystallins - analysis; Electrophoresis, Polyacrylamide Gel; Humans; Hydrogen-Ion Concentration; Molecular Weight; Sulfhydryl Compounds - analysis; Temperature
• ISSN: 0014-4835; 1096-0007
• DOI: 10.1016/0014-4835(73)90307-2

Studies on alpha-crystallin separated from human senile lenses, either transparent or with different degrees of senile cataractous changes, have not shown appreciable differences in the relative amount of the high and low molecular weight fractions of this protein. Both in human normal senile lens and in senile cataract the larger-sized population, with molecular weight above 1 × 10 7, accounts for about 85% of all the alpha-crystallin extracted from the whole lens. Gel electrophoresis analysis in the presence of urea or of sodium dodecylsulphate, and amino acid composition gave essentially similar results in normal and cataractous alpha-crystallin. Titration of sulphydryl groups of alpha-crystallin indicated a lower availability to p-mercuribenzoate in advanced stages of cortical and nuclear cataracts. Under the experimental conditions used, no evidence has been found that lens opacification in human senile cataract is associated with the accumulation of a high molecular weight population of alpha-crystallin.