Human lens membrane proteinase: Purification and age-related distributional changes in the water-soluble and insoluble protein fractions

Background/Objective:: The aim of this systematic review is to identify all the available data on human lens proteomics with a critical role to age-related cataract formation in order to elucidate the physiopathology of the aging lens. Materials and Methods:: We searched on Medline and Cochrane databases. The search generated 328 manuscripts. We included nine original proteomic studies that investigated human cataractous lenses. Results:: Deamidation was the major age-related post-translational modification. There was a significant increase in the amount of αA-crystallin D-isoAsp58 present at all ages, while an increase in the extent of Trp oxidation was apparent in cataract lenses when compared to aged normal lenses. During aging, enzymes with oxidized cysteine at critical sites included GAPDH, glutathione synthase, aldehyde dehydrogenase, sorbitol dehydrogenase, and PARK7. Conclusion:: D-isoAsp in αA crystallin could be associated with the development of age-related cataract in human, by contributing to the denaturation of a crystallin, and decreasing its ability to act as a chaperone. Oxidation of Trp may be associated with nuclear cataract formation in human, while the role of oxidant stress in age-related cataract formation is dominant.

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Nanoceria Prevents Glucose-Induced Protein Glycation in Eye Lens Cells

Nanomaterials ◽

10.3390/nano11061473 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1473

Author(s):

Belal I. Hanafy ◽

Gareth W. V. Cave ◽

Yvonne Barnett ◽

Barbara K. Pierscionek

Keyword(s):

Protein Glycation ◽

Human Lens ◽

Lens Epithelial Cells ◽

Oxide Nanoparticles ◽

Lens Protein ◽

Oxygen Species ◽

Human Lens Epithelial Cells ◽

Age Related ◽

Age Related Changes

Cerium oxide nanoparticles (nanoceria) are generally known for their recyclable antioxidative properties making them an appealing biomaterial for protecting against physiological and pathological age-related changes that are caused by reactive oxygen species (ROS). Cataract is one such pathology that has been associated with oxidation and glycation of the lens proteins (crystallins) leading to aggregation and opacification. A novel coated nanoceria formulation has been previously shown to enter the human lens epithelial cells (HLECs) and protect them from oxidative stress induced by hydrogen peroxide (H2O2). In this work, the mechanism of nanoceria uptake in HLECs is studied and multiple anti-cataractogenic properties are assessed in vitro. Our results show that the nanoceria provide multiple beneficial actions to delay cataract progression by (1) acting as a catalase mimetic in cells with inhibited catalase, (2) improving reduced to oxidised glutathione ratio (GSH/GSSG) in HLECs, and (3) inhibiting the non-enzymatic glucose-induced glycation of the chaperone lens protein α-crystallin. Given the multifactorial nature of cataract progression, the varied actions of nanoceria render them promising candidates for potential non-surgical therapeutic treatment.

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In vivo carbamylation and acetylation of water-soluble human lens αB-crystallin lysine 92

Protein Science ◽

10.1110/ps.40901 ◽

2001 ◽

Vol 10 (6) ◽

pp. 1130-1136 ◽

Cited By ~ 39

Author(s):

Veniamin N. Lapko ◽

David L. Smith ◽

Jean B. Smith

Keyword(s):

Water Soluble ◽

Human Lens ◽

Αb Crystallin

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Age-Related Changes in Normal and Cataractous Human Lens Crystallins, Separated by Fast-Performance Liquid Chromatography

Ophthalmic Research ◽

10.1159/000267406 ◽

1994 ◽

Vol 26 (3) ◽

pp. 149-157 ◽

Cited By ~ 3

Author(s):

P.C. Pereira ◽

J.S. Ramalho ◽

C.J. Faro ◽

M.C. Mota

Keyword(s):

Liquid Chromatography ◽

Human Lens ◽

Lens Crystallins ◽

Age Related Changes

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Studies on Chitin

Australian Journal of Biological Sciences ◽

10.1071/bi9550530 ◽

1955 ◽

Vol 8 (4) ◽

pp. 530 ◽

Cited By ~ 21

Author(s):

RH Hackman

Keyword(s):

Isoelectric Point ◽

Salt Concentration ◽

Water Soluble ◽

Protein Fractions ◽

Cuticular Protein ◽

Adsorbed Protein ◽

Effects Of Ph

The effects of pH, salt concentration, and temperature on the adsorption of a water-soluble insect cuticular protein to chitin have been investigated. The adsorption is dependent upon pH, decreasing rapidly as the pH increases from the region of the isoelectric point of the protein. Increase in salt concentration decreases adsorption but the adsorption appears to be little influenced by changes in temperature. Tyrosine-rich protein fractions are preferentially adsorbed. The adsorption is partly irreversible and an increase to pH 9 is necessary before all the adsorbed protein can be removed. It is concluded that there is only a weak bonding between the chitin and the water-soluble cuticular protein.

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