Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.54 (calpain 3)
 430 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cloned human CD4+ T cell lines specific for the house dust mite Dermatophagoides pteronyssinus were used to map minimal T cell activation-inducing epitopes on the Group I allergen in D. pteronyssinus extracts (Der p I) molecule. Most of these Der p I-specific T cell clones expressed different TCR V alpha and V beta gene products. Using recombinant deletion proteins, three T cell epitopes were identified on the Der p I molecule; p45-67 and p117-143 were recognized by HLA-DR7-restricted T cells, whereas p94-104 was recognized in the context of HLA-DR2, DRw11 (DR5), and -DR8 molecules. This degenerate class II MHC restriction appears to be due to shared Phe and Asp residues at positions 67 and 70, respectively, in the third variable domain of the HLA-DR beta chain. All three T cell epitopes induced Th2-like cytokine production profiles by the Der p I-specific T cell clones, which were characterized by the production of very high levels of IL-4 and IL-5, as compared with those secreted by tetanus toxin-specific T cell clones derived from the same patients, but no or low amounts of IL-2 and IFN-gamma. This Th2-like production profile was, however, not an intrinsic property of the Der p I-specific T cells, but was dependent upon their mode of activation. Stimulation with Con A also induced very low or no measurable levels of IL-2 and IFN-gamma, whereas activation with TPA and the calcium ionophore A23187 resulted in the production of high levels of IL-4, IL-5, IL-2, and IFN-gamma. These results indicate that Der p I-specific T cell clones are not defective in their capacity to produce high levels of Th1 cytokines.
 ...
PMID:T cell activation-inducing epitopes of the house dust mite allergen Der p I. Proliferation and lymphokine production patterns by Der p I-specific CD4+ T cell clones. 137 May 14

While conventional calpains, m- and mu-calpains named according to their calcium-dependence, are expressed in almost every tissues, mRNA of newly identified p94, which has a significant sequence similarity to the conventional calpain large subunits, is abundantly expressed only in skeletal muscle. In addition to this specific expression, p94 is distinct from conventional calpains in that it contains three unique regions showing no similarity to conventional calpain subunits. When rat and human p94 are compared, overall sequence similarity is 94.0%, which is close to those for m- and mu-calpain large subunits; 93.1% and 95.4% between human and rabbit, respectively, suggesting the evolutionary importance of p94. These calpain large subunit proteins, p94, m- and mu-types, can be considered to constitute a super family, whose p94, m- and mu-types represent the three major types. Sequences of the calpain large-subunit family members, including the recently reported Schistosoma calpain, are compared. Their evolutionary correlation and function are discussed on the basis of the results thus far obtained.
 ...
PMID:Sequence comparison among muscle-specific calpain, p94, and calpain subunits. 142 Mar 33

Recently there have been reports on high-molecular mass components of Borrelia burgdorferi, namely the p100, p94 and p83, which claimed these proteins to be specific marker antigens for the serodiagnosis of late Lyme borreliosis. The nucleotide sequences of the p100 and p83 have been published. The alignment of the deduced N-terminal amino acid sequences with the N-terminal sequence of the p94 now provides evidence that all three proteins are identical.
 ...
PMID:Evidence that Borrelia burgdorferi immunodominant proteins p100, p94 and p83 are identical. 142 83

Peptidyl acyloxymethyl ketones, previously established as potent inactivators of the lysosomal cysteine proteinase cathepsin B, were evaluated against smooth-muscle calpain, a member of the family of Ca(2+)-dependent cysteine proteinases. Only modest rates of time-dependent inhibition could be achieved, even with peptidyl affinity groups optimized for calpain and linked to a carboxylate leaving group of very low pKa [2,6-(CF3)2PhCOO-, pKa 0.58]. Selective inactivation of cathespin B versus calpain was consistently observed with this type of inhibitor. Examination of other potential inhibitors revealed a rank order of potency against calpain to be: peptidyl sulphonium methyl ketones > fluoromethyl ketones, diazomethyl ketones >> acyloxymethyl ketones, an order which differs sharply from that found for cathespin B.
 ...
PMID:Comparative behaviour of calpain and cathepsin B toward peptidyl acyloxymethyl ketones, sulphonium methyl ketones and other potential inhibitors of cysteine proteinases. 147 90

Fractionation of a cytosolic extract of HeLa cells revealed the existence of a highly active protein tyrosine kinase. Chromatographic fractionation of the extract resulted in partial purification of a single enzymatic activity that coeluted with a 94-kDa polypeptide. In vitro phosphorylation of the isolated enzyme showed that p94 was the only polypeptide phosphorylated and only the tyrosine residue(s) was (were) modified. The fractionated enzyme (p94 kinase) also phosphorylated a number of other nonspecific substrates exclusively on tyrosine residues. Unlike other protein tyrosine kinases that have been characterized, p94 kinase is relatively insensitive to inhibition by the isoflavone genistein. Using two different antisera, we provided evidence that the HeLa p94 kinase is most likely the FER gene product, which was previously shown to be expressed in a wide variety of cell types. These results represent the first biochemical characterization of the cellular FER gene product and also provide a basis for studying the biochemistry of tyrosine kinase function in HeLa cells.
 ...
PMID:Identification and characterization of a cytosolic protein tyrosine kinase of HeLa cells. 155 92

The objectives of this experiment were to assess effects of animal age and castration on activities of calpain I, calpain II, and calpastatin in sheep skeletal muscle. Ten newborn male lambs (2.9 kg), six weaned wethers (23.2 kg), six weaned rams (22.2 kg), six market wethers (55.4 kg), and six market rams (60.2 kg) were slaughtered and samples of biceps femoris were taken for assay of calpain I (micromolar calcium-dependent proteinase), calpain II (millimolar calcium-dependent proteinase), and calpastatin. Preweaning weight gain was similar for rams and wethers; however, postweaning ram growth exceeded (P less than .05) that of wethers. Ram biceps femoris weights at market were greater than those of wethers (P less than .05). Irrespective of age or gender, activity of calpain II was two- to threefold greater than that of calpain I. Muscle calpastatin activity was severa fold higher than calpain I and II activities. Activities of calpains and calpastatin declined (P less than .05) between birth and weaning. A portion of these losses were due to a dilution effect caused by accumulation of muscle proteins. Neonatal attenuation of calpain activities may underlie age-related attenuation of fractional rates of muscle protein degradation. Although ram muscle growth exceeded that of wethers, no differences (P greater than .05) in activities of muscle calpains or calpastatin were detected between these two groups at weaning or at market weight. Hence, castration did not influence lamb muscle growth by altering muscle calpain or calpastatin activities.
 ...
PMID:Effects of age and castration on activities of calpains and calpastatin in sheep skeletal muscle. 171 52

Our objectives were to characterize events underlying changes in skeletal muscle calpain and calpastatin activities, using maturation as a model. Muscle samples were taken from rabbits of four ages (newborn and 1, 2, and 5 mo old). Concentrations of RNA and protein and activities of calpains I and II and calpastatin were determined. Steady-state concentrations of mRNAs encoding calpain I, calpain II, calpastatin, alpha- and beta-tubulin, and beta-actin were determined using Northern blot analysis. Calpain and calpastatin activities declined markedly between birth and 1 mo of age and remained unchanged thereafter. Several factors accounted for the neonatal losses of calpains and calpastatin. First, muscle protein concentration increased between birth and 1 mo of age and diluted calpain and calpastatin specific activities. Second, there was a marked reduction of muscle RNA concentration between birth and 1 mo of age, which indicates that protein synthetic capacity declined with age. Finally, calpastatin mRNA concentration declined between birth and 1 mo of age and further contributed to developmental losses of calpastatin activity. Calpain I mRNA concentration was unaffected by age, and although calpain II mRNA concentration declined with age, losses were not detected between birth and 1 mo; hence age-related changes in calpain I and II activities are not mediated at the mRNA level. The age-related reductions in calpain II and calpastatin mRNA concentrations resembled age-related changes in alpha- and beta-tubulin and beta-actin mRNA concentration.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Determination of skeletal muscle calpain and calpastatin activities during maturation. 176 27

Two forms of calpastatin, differing in their specificity for the homologous calpain isozymes I and II, have been separated from rat skeletal muscle extracts and purified to homogeneity. Calpastatin I, the first form to elute in chromatography on DE32, is more effective against calpain I, while calpastatin II is more effective as an inhibitor of calpain II. Based on their molecular mass (approximately 105 kDa) both calpastatin forms belong to the high molecular mass class found in muscles of other animal species (Murachi, T., 1989, Biochem. Int. 18, 263-294). For calpain I, which is active with low (mu-M) concentrations of Ca2+, maximum inhibition with either calpastatin form was observed over a wide range of Ca2+ concentrations. With calpain II, which requires high (mM) concentrations of Ca2+ for activity, maximum inhibition required Ca2+ concentrations above 1 mM. Both calpastatin forms were found to be highly sensitive to degradation by calpain II, but almost completely resistant to degradation by calpain I. Degradation of calpastatin by calpain II is competitively inhibited by the addition of a calpain substrate. Isovaleryl carnitine (IVC), an intermediate product of L-leucine catabolism, previously demonstrated to be a potent and specific activator of rat skeletal muscle calpain II (Pontremoli, S., Melloni, E., Viotti, P. L., Michetti, M., Di Lisa, F., and Siliprandi, N., 1990. Biochem. Biophys. Res. Commun. 167, 373-380) greatly enhances the rate of degradation of calpastatins by calpain II. IVC, which decreases the Ca2+ requirement for maximal calpain II activity, also decreases the concentration of Ca2+ required for digestion of the inhibitor. For calpain II, regulation by either calpastatins may occur only in the presence of high [Ca2+].
 ...
PMID:Identification of two calpastatin forms in rat skeletal muscle and their susceptibility to digestion by homologous calpains. 189 54

Only the 80-kD catalytic subunit of smooth muscle calpain II shows a change in intrinsic fluorescence on binding calcium, but both the 80-kD and 30-kD subunits show fluorescence changes in bound toluidinyl-naphthalenesulphonate as a result of calcium binding. Both subunits also show changes in intrinsic fluorescence in the presence of calmidazolium and felodipine. These studies indicate that both subunits have binding sites for calcium and the calmodulin antagonists, which are probably located in the calmodulin-like domain of each subunit.
 ...
PMID:Effects of calcium and calmodulin antagonists on calpain II subunit conformations. 209 9

Calcium dependent proteases (calpains, CAPNs, E.C.3.4.22.17) constitute a family of proteins which share a homologous cysteine-protease domain (large subunits, L1, L2, and L3) and an E-F hand Ca2(+)-binding domain (L1, L2, L3, and small subunit, S). We have mapped the genes for four calpain proteins (L1, L2, L3, and S) on four distinct human chromosomes by a combination of spot-blot hybridization to flow-sorted chromosomes and Southern hybridization of DNAs from a human x mouse hybrid cell panel. The genes for calpain L1 (CAPN1, large subunit of calpain I), L2 (CAPN2, large subunit of calpain II), L3 (CAPN3, a protein related to the large subunits), and S (CAPN4, a small subunit common to calpains I and II) were assigned to human chromosomes 11, 1, 15, and 19, respectively.
 ...
PMID:Four genes for the calpain family locate on four distinct human chromosomes. 220 92


1 2 3 4 5 6 7 8 9 10 Next >>