01 September 2005
Calpains: enzymes of vision?Suman Biswas, Frederick Harris, Sarah Dennison, Jai Paul Singh, David Phoenix
Med Sci Monit 2005; 11(9): RA301-310 :: ID: 428466
Globally, cataract accounts for the majority of cases of treatable blindness and the lens opacification associated with cataract is primarily due to the insolubilisation of crystallins, proteins essential for the transparency of the lens. Recent studies have suggested that a major cause of this insolubilisation may be the unregulated proteolysis of crystallins by calpains. These are intracellular cysteine proteases whose activation requires the presence of Ca2+ and elevated levels of lens Ca2+ is a condition strongly associated with cataract. Calpain 2 appears to be the major calpain involved in animal cataractogenesis and the strongest candidate of the calpains for a role in human cataractogenesis but despite intensive study, the mechanism(s) underlying activation of the enzyme both in cataractogenesis and normal lens function are unclear. Recently, the high-resolution structure of calpain 2 was recently solved and a structural basis for the Ca2+-dependence of the enzyme's activity has been putatively established. Other recent studies have suggested that membrane interaction(s) may play a role in lowering the Ca2+-requirements of calpain 2 activation and most recently, strongly supporting this suggestion, several lipid interactive regions in the enzyme have been identified. Here, we review progress in understanding of the role played by calpain 2 in cataractogenesis and the possible use of inhibitors of the enzyme as anti-cataract agents.
Keywords: Cataract - metabolism, Calpain - metabolism, Calcium - metabolism, Crystallins - metabolism, Cysteine Proteinase Inhibitors - therapeutic use, Enzyme Activation, Lens, Crystalline - metabolism, Models, Biological, Models, Molecular, Solubility, Vision, Ocular - physiology
01 May 2023 : EditorialEditorial: Twenty Years On from Sequencing the Human Genome, Personalized/Precision Oncology Prepares to Meet the Challenges of Checkpoint Inhibitor Therapy
Med Sci Monit 2023; 29:e940911
31 May 2023 : Review articlePrevalence, Diagnosis, and Management of Eclampsia and the Need for Improved Maternal Care: A Review
Med Sci Monit In Press; DOI: 10.12659/MSM.939919
30 May 2023 : Clinical ResearchA Case-Control Study of Cognitive Function in Patients with End-Stage Renal Disease Before and After Hemodi...
Med Sci Monit In Press; DOI: 10.12659/MSM.940409
30 May 2023 : Review articleA Review of the Role of the Zebrafish (Danio reiro) in Preclinical and Clinical Models of Biomarker Identif...
Med Sci Monit In Press; DOI: 10.12659/MSM.940550
30 May 2023 : Database AnalysisThe COVID-19 Crisis and the Incidence of Alcohol-Related Deaths in Poland
Med Sci Monit In Press; DOI: 10.12659/MSM.940904
Most Viewed Current Articles
13 Nov 2021 : Clinical ResearchAcceptance of COVID-19 Vaccination and Its Associated Factors Among Cancer Patients Attending the Oncology ...
Med Sci Monit 2021; 27:e932788
30 Dec 2021 : Clinical ResearchRetrospective Study of Outcomes and Hospitalization Rates of Patients in Italy with a Confirmed Diagnosis o...
Med Sci Monit 2021; 27:e935379
08 Mar 2022 : Review articleA Review of the Potential Roles of Antioxidant and Anti-Inflammatory Pharmacological Approaches for the Man...
Med Sci Monit 2022; 28:e936292
01 Jan 2022 : EditorialEditorial: Current Status of Oral Antiviral Drug Treatments for SARS-CoV-2 Infection in Non-Hospitalized Pa...
Med Sci Monit 2022; 28:e935952