Possible changes in secondary structure and composition of human lens capsules in hereditary congenital cataract

Abstract

Scanty information is available on the changes in conformational structure and composition of human lens capsule in cases of hereditary congenital cataract. The purpose of this study was to use Fourier-transformed infrared (FT-IR) spectroscopy to determine the secondary structure and composition of hereditary cataractous human lens capsule, as compared with normal human lens capsule. FT-IR spectroscopy with the Fourier self-deconvolution and curve-fitting program was performed, and second-derivative analysis was used to verify the peak positions and assignments of the IR spectra. The curve-fit FT-IR spectra revealed that the content of hydroxylysine and arginine were clearly higher in the lens capsule of the hereditary congenital patient, but the content of aspartic acid significantly lower, than in normal human lens capsules. The secondary conformational changes in alpha-helix, triple helix and random coil structures were important findings in the lens capsule of a hereditary cataractous patient. Possible alterations in secondary structures and compositions of lens capsule are observed in the hereditary congenital cataractous patient by using FT-IR spectroscopy with curve-fitting and second-derivative analysis.