Calcium proteinase activity

Gupta, R. P, and Abou-Dotiia, M. B, (1995). Diisopropyl phos-phorofluoridate (DFP) treatment alters calcium-activated proteinase activity and cytaskeleial proteins of the hen. sciatic nerve. Brain Res. 17, 162-166. 

Montreal platelet syndrome Apparent defect in calpain, a calcium-activated proteinase protein that may be responsible for spontaneous platelet aggregation... 

Okita, J. R., Erojmovic, M. M., Kristopeit, S., et al., Montreal platelet syndrome A defect in calcium-activated neutral proteinase (Calpain). Blood 74, 715-721 (1989). 

Saito, K., Elce, J.S., Hamos, J.E., and Nixon, R.A., 1993, Widespread Activation of Calcium-Activated Neutral Proteinase (Calpain) in the Brain in Alzheimer Disease A Potential Molecular Basis for Neuronal Degeneration, Proc. Natl. Acad. Sci. U. S. A., 90, 2628-2632 Kawai, H., Akaike, M., Kunishige, M., Inui, T., Adachi, K., Kimura, C., Kawajiri, M., Nishida, Y., Endo, I., and Kashiwagi, S. et al., 1998, Clinical, pathological, and genetic features of limb-girdle muscular dystrophy type 2A with new calpain 3 gene mutations in seven patients from three Japanese families, Muscle Nerve, 21, 1493-1501... 

Pinter, M., and Friedrich, P., 1988, The calcium dependent proteolytic system calpain-calpatatin in Drosophila melanogaster, Biochem J., 253, 467-473 Pinter, M., Stierandova, A., and Friedrich, P., 1992, Purification and characterization o a Ca2 activated thiol protease from drosophila melanogaster, Biochemistry, 31, 8201-8206 Pontremoli, S., Melloni, E., Michetti, M., Salamino, F., Sparatore, B., Horecker, B., 1988, An endogenous activator of the Ca2+ -dependent proteinase of human neutrophils that increases its affinity for Ca2+, Proc. Natl. Acad. Sci., USA, 85, 1740-1743... 

Saito, K., Elce, J. S., Hamos, J. E., and Nixon, R. A. (1993). Widespread activation of calcium-activated neutral proteinase (calpain) in the brain in Alzheimer disease a potential molecular basis for neuronal degeneration. Proc Natl Acad Sci U S A 90, 2628-2632. 

Another nonlysosomal protein degradative system is dependent on calcium ions. They combine with specific protein residues in close proximity to each other proline, glutamate, serine, and threonine (PEST sequences). It is believed that a calcium-requiring proteinase (a metalloenzyme) recognizes the calcium and combines with it, thus achieving an active status, and then hydrolyzes the protein in the vicinity of the PEST sequence. 

Andresen, K., Tom, T. D. and Strand, M. (1991) Characterization of cDNA clones encoding a novel calcium-activated neutral proteinase from Schistosoma mansoni. J. Biol. Chem. 266 15085-15090. 

Suzuki, K. Tsuji, S. (1982). Synergistic activation of calcium-activated neutral proteinase by Mn and Ca. FEBS Lett., 140, 16-18. 

Gross proteolytic activity of lactic acid bacteria is the sum of proteinase and peptidase activity. Normally, proteinases are plasmid-encoded and the enzymes are, in most cases, associated with the cell wall by a calcium ion-dependent binding. The synthesis of proteinase seems to be regulated by the growth medium (Exterkate, 1985 Bruinenberg et al., 1992). Normally, milk as growth medium forces strains to produce a high level of proteinase. 

Caldolysin is the trivial name of the serine proteinase from T. aquaticus strain T351 [284]. This enzyme did not have detectable esterase aetivity and hydrolysis of small peptides of less than four amino acids was not observed. The enzyme was highly stable in the presenee of ealcium ions. Caldolysin bound six calcium ions per molecule of enzyme, there being both high and low affinity binding sites [285]. Stability of apocaldolysin (i.e. caldolysin treated with EDTA to remove all calcium ions) was restored upon incubation with either calcium or lanthanide ions, the latter giving a lanthanide-caldolysin complex more stable than the native enzyme. Strontium ions were the only other divalent metal ions tested that could restore more than 50% activity. 

Dozens of different peptides have been identified in cheeses. Most of them arise from and -caseins and a few are from aj2-and K-caseins. The proteinases involved in hydrolysis of aj -casein are mainly cathepsin D originating from milk and cell-envelope proteinase from thermophilic starters, while P- and aj2-caseins are mainly hydrolysed by plasmin. Moreover, peptidases from starters are also active throughout the ripening process, presumably similar to those from non-starter lactic acid bacteria. For example, the bitterness of mature Gouda cheese is caused by calcium and magnesium chlorides, some bitter-tasting free amino acids and is modified by peptides, which arise from the hydrolysis of fS-casein (such as decapeptide Tyr-Pro-Phe-Pro-Gly-Pro-Ile-His-Asn-Ser and derived nonanpeptide without the terminal serine) and casein (tetrapeptide Leu-Pro-Gln-Glu). 

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