Human lens carbonic anhydrases. purification and Properties

Abstract

ABSTRACT.Purpose: To isolate and characterize carbonic anhydrase (CA) isozymes of human lenses. Methods: Affinity chromatography was used to separate CA isozymes, as monitored by an immunosorbent assay. Amino acid analysis was done on the antigenic CAII. CA catalytic activity and its sensitivity to inhibition was measured on soluble and membrane-bound CA isozymes. Results: The lens contains 0.25, 9, and 2 mg/g wet weight of CAI, II, and III, respectively. Almost all of the CA catalytic activity originates from CAII. Plasma membranes had a CA activity that was inhibited like the membranebound isozyme CAIV.

ceRNA network construction and identification of hub genes as novel therapeutic targets for age-related cataracts using bioinformatics

“…Human CA variants have been linked to glaucoma, macular edema, ulcers, obesity, and cancer ( Cabaleiro-Lago & Lundqvist, 2020 ). A study ( Wistrand, 1999 ) investigating human lens CA demonstrated that the CA activity originates from CA 1, 2 and 3 in the cytoplasm , and from CA4 in the plasma membranes of lens epithelium and fibers in normal patients, and there was no CA activity observed in the supernatant of senile cataract lenses. As studies ( Wistrand, 1999 ; Wistrand, 2000 ) have shown that the chronic intake of CA inhibitor does not seem to induce lens opacification (signs of cataract), we hypothesize that the down-regulation of CA2 observed in our study may be a protective response to oxidative stress.…”