Comparative action of calpain on erythrocyte Ca2+-pumping ATPase in sickle cell anaemia, essential hypertension and kwashiorkor. Issue 3 (June 1990)

• Record Type: Journal Article
• Authors: Olorunsogo, O. O.; Agbolade, F. O.; Owojuyigbe, S. O.; Adebisi, J. A.; Adebayo, A. O.; Okunade, W. G.
• Is Part Of: Bioscience reports. Volume 10:Issue 3(1990)
• Page Start: 281
• Page End: 291
• Publication Date: 1990-06
• Subjects: calpain -- Ca2+-ATPase -- erythrocyte -- sickle cell anaemia -- hypertension -- kwashiorkor; Molecular biology -- Periodicals; Cytology -- Periodicals; 572.8
• DOI: 10.1007/BF01117244
• Languages: English
• ISSNs: 0144-8463

Abstract

Abstract : Calpain, a calcium-dependent, neutral cysteine-protease was purified from the erythrocyte cytosol of subjects having essential hypertension (HTN), sickle cell anaemia, (SCA), or kwashiorkor (KWA). Identical electrophoretic mobility on SDS-polyacrylamide gradient gel, sensitivity to micromolar amounts of Ca 2+, absolute requirement for a reducing environment and a high susceptibility to inhibition by leupeptin and thiol-group modifying reagents confirm that calpain preparations from these erythrocytes are equivalent to calpain I. Whereas the extent of calpain activation of erythrocyte membrane Ca 2+ -pumping ATPase of normal subjects was almost equal to that due to calmodulin, calpain activation of the HTN and SCA pump was greater than activation by calmodulin. Like in normal membranes, exogenous calmodulin protected the Ca 2+ -pumping ATPase of these erythrocytes against calpainization; the degree of protection by calmodulin is least in SCA and HTN. Electrophoretic separation of erythrocyte membranes and the purified Ca 2+ -pumping ATPase of HTN, SCA and KWA subjects does not indicate the presence of fragments resulting from the proteolytic action of calpain.