caa a22 4500 378853147 CHVBK 20180305123328.0 cr unu---uuuuu 161128e20030820xx s 000 0 eng 10.1515/BC.2003.131 doi (NATIONALLICENCE)gruyter-10.1515/BC.2003.131 The Molecular Chaperone, α-Crystallin, Protects against Loss of Antigenicity and Activity of Esterase Caused by Sugars, Sugar Phosphate and a Steroid [Elektronische Daten] [H. Yan, J. J. Harding] Previously we showed that glycation-induced inactivation and loss of antigenicity of enzymes occur simultaneously. α-Crystallin, a major structural protein of the mammalian lens, prevents the aggregation of other proteins and protects enzyme function against post-translational modification in vitro. However, it is not known whether αcrystallin can also protect against loss of antigenicity of enzymes. Esterase activity in the lens is decreased in senile cataract and diabetes. We investigated the loss of antigenicity of esterase caused by different insults and the ability of α-crystallin to protect. Inactivation of carboxylesterase by sugars, fructose 6-phosphate (F6P) and a steroid, prednisolone-21-hemisuccinate (P-21-H), was measured spectrophotometrically in the presence and absence of α-crystallin, while loss of antigenicity was monitored simultaneously using an immunoprecipitation method. The esterase was progressively inactivated by fructose, F6P, ribose, and P 21-H. Bovine α-crystallin fully protected against inactivation of esterase by all four compounds, and also protected against loss of antigenicity of the esterase by fructose, ribose and P-21-H at a molar ratio of 1:1. The results indicated that α-crystallin, under our experimental conditions, clearly exhibited the ability to prevent loss of antigenicity and inactivation of esterase. The protective effect of αcrystallin against loss of antigenicity indicates a novel aspect of its chaperoning function. Copyright © 2003 by Walter de Gruyter GmbH & Co. KG Biochemistry nationallicence Molecular biology nationallicence Cellular biology nationallicence Yan H. aut Harding J. J. aut Biological Chemistry Walter de Gruyter 384/8(2003-08-20), 1185-1194 1431-6730 384:8<1185 2003 384 bchm https://doi.org/10.1515/BC.2003.131 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1515/BC.2003.131 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yan H. aut NATIONALLICENCE 700 1- Harding J. J. aut NATIONALLICENCE 773 0- Biological Chemistry Walter de Gruyter 384/8(2003-08-20), 1185-1194 1431-6730 384:8<1185 2003 384 bchm CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter