Abstract
The camel has several biochemical, physiological, and anatomical features to withstand the harsh desert climate. Camel eye lens contains a novel protein (zeta-crystallin) in bulk quantity. Previous reports suggest that non-enzymatic glycation of eye lens proteins plays an important role in the etiology of cataract. In this study, we have characterized the role of glucose, fructose, and methylglyoxal (MGO) in the glycation of camel lens zeta-crystallin. From the results obtained, it was found that MGO reacted rapidly, fructose reacted moderately, and glucose was the least reactive even after prolonged incubation (N100 days). Glycation with MGO and fructose led to changes in the structure of zeta-crystallin, while glucose had no remarkable effect. The surface hydrophobicity did not change and no aggregates or amyloid fibrils were observed in the glycated zeta-crystallin. Moreover, the secondary structure of glycated zeta-crystallin remained similar after glycation. Our results suggested that due to natural adaptation, the camel lens protein zeta-crystallin retained its structure and solubility even after glycation to perform the single known function of the lens proteins: to focus unscattered light on the retina. (c) 2020 Elsevier B.V. All rights reserved.