CAMEL LENS CRYSTALLINS GLYCOSYLATION AND HIGH-MOLECULAR-WEIGHT AGGREGATE FORMATION IN THE PRESENCE OF FERROUS-IONS AND GLUCOSE

The incubation of camel lens cortex homogenate with 100μM ferrous ions and 5.5mM glucose under sterile conditions caused rapid protein aggregation, but little or no reaction was seen with either 100μM ferrous ions or 5.5mM glucose alone. The formation of glycosylated high molecular weight (HMW) protein aggregates was confirmed by light scattering studies, a decreased level of free -SH groups, incorporation of [14C]-glucose and elution of HMW protein aggregate just after the void volume of a Sephacryl S-1000 column. The bonding involved in the formation of these aggregates was found to be mainly disulfide in nature. Isoelectric focusing (IEF) in the presence and absence of reducing conditions indicated that gamma-crystallins may be involved in the formation of HMW protein aggregates. The modifications observed were found to mimic those seen in cataractous lenses. © 1990 Academic Press, Inc.