[Study on human gamma-crystallins: V. Non-enzymatic glycation of fetal lens gamma 1- and gamma 3-crystallins in vitro].
OBJECTIVE
To compare the non-enzymatic glycation of different human fetal gamma-crystallins induced by glucose and fructose.


METHODS
gamma 1- and gamma 2-crystallin were separated by the Sephadex gel chromatography from human fetal lenses. The non-enzymatic glycations of these gamma-crystallins were conducted by incubating with glucose or fructose at 37 degrees C for 20 days. The opacity and pellet formation as well as changes on SDS-polyacrymide gel electrophoresis (SDS-PAGE) pattern and blue fluorescence production were observed.


RESULTS
Although the two gamma-crystallins displayed similar alterations, gamma 1-crystallin was easier to produce aggregation and insolublization in early stage (i.e. 3 days). SDS-PAGE showed that there were aggregates, formed through disulfide and non-disulfide cross-links, and degraded peptides produced. The blue fluorescence increased in glycated gamma 3-crystalline solution. Fructose had more significant effects (i.e. aggregation, degradation, producing blue fluorescence) on gamma-crystallins as compared with glucose.


CONCLUSIONS
Human fetal gamma 1- and gamma 3-crystallins are sensitive, at different extent (gamma 1 > gamma 3), to response to non-enzymatic glycation, and fructose has stronger effect than glucose on the glycation.
Wu
K
K
Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, Guangzhou, China.
Pan
S
S
Liang
S
S
Li
S
S
D003459:Crystallins / Q000737:chemistry*; D005333:Fetus; D005632:Fructose; D005947:Glucose; D006031:Glycosylation; D006801:Humans
D003459:Crystallins; D005632:Fructose; D005947:Glucose