The interaction between the cysteine proteases calpain and caspases during renal ischemia-reperfusion (I/R) was investigated. An increase in the activity of calpain, as determined by 1) the appearance of calpain-mediated spectrin breakdown products and 2) the conversion of procalpain to active calpain, was demonstrated. Because intracellular calpain activity is regulated by calpastatin, the eff...

An indirect antibody ELISA was developed for rapid and sensitive quantification of skeletal muscle calpastatin. Polyclonal antibodies were raised in rabbits against recombinant calpastatin, corresponding to domains 2, 3, and 4 of bovine skeletal muscle calpastatin. Western blot analysis revealed that these antibodies specifically recognize an immunoreactive calpastatin protein of approximately ...

Tenderness is a key component of palatability, which influences consumers' perception of meat quality. There are a variety of factors that contribute to the tenderness of beef carcasses, including postmortem proteolysis. A more complete understanding of this biological mechanism regulating tenderness is needed to ensure consistently tender beef. Numerous reports indicate µ-calpain is primarily ...

An indirect antibody ELISA was developed for rapid and sensitive quantification of skeletal muscle calpastatin. Polyclonal antibodies were raised in rabbits against recombinant calpastatin, corresponding to domains 2, 3, and 4 of bovine skeletal muscle calpastatin. Western blot analysis revealed that these antibodies specifically recognize an immunoreactive calpastatin protein of approximately ...

Calpastatin is a specific inhibitor of the calpains. Calpains play a key role in postmortem tenderization of meat and have been hypothesized to be involved in muscle protein degradation in living tissue. Isolation, cloning of complementary DNA, and nucleotide sequencing of bovine calpastatin from the longissimus muscle have been completed. Two clones were identified that encompass the entire co...

Microsphere embolism (ME)-induced cerebral ischemia can elicit various pathological events leading to neuronal death. Western blotting and immunohistochemical studies revealed that expression of calpastatin, an endogenous calpain inhibitor, decreased after ME induction. Calpain activation after ME was apparently due to, in part, a decrease in calpastatin in a late phase of neuronal injury. The ...

Calpastatin is an endogenous inhibitor of calpain (calcium-dependent cysteine protease). Calpastatin activityis highly related to the rate of protein turnover and rate of meat tenderization. In order to characterize thestructure of calpastatin in Iranian Afshari breed of sheep, intron 6 and partial exon 7 of the L domain wereamplified and sequenced. A fragment of approximately...

We have previously reported that, in neuroblastoma LAN-5 cells, calpastatin is in an aggregated state, close to the cell nucleus [de Tullio, Passalacqua, Averna, Salamino, Melloni and Pontremoli (1999) Biochem. J. 343, 467-472]. In the present paper, we demonstrate that aggregated calpastatin is predominantly in a phosphorylated state. An increase in intracellular free [Ca2+] induces both depho...

Glioblastoma (GBM) is an aggressive, malignant brain tumor that inevitably develops resistance to conventional chemotherapy and radiation treatments. In order to identify signaling pathways involved in the development of radiation resistance, we performed mass spectrometry-based phospho-proteomic profiling of GBM cell lines and normal human astrocytes before and after radiation treatment. We fo...

Two cysteine protease families (caspase and calpain) participate in apoptosis. Here we report that the endogenous calpain inhibitor calpastatin is fragmented by caspase(s) to various extents during early apoptosis in two cell types. In anti-fas or staurosporine-treated Jurkat T-cells, the high-molecular-weight form (HMW) of calpastatin (apparent Mr 110 K) was extensively degraded to immunoreact...