We isolated calcium-labile mitotic spindles from eggs of the sea urchin Lytechinus variegatus, using a low ionic strength, EGTA lysis buffer that contined 5.0 mM EGTA, 0.5 mM MgCl2, 10-50 mM PIPES, pH 6.8, with 1% Nonidet P-40 (detergent) and 20-25% glycerol. Isolated spindles were stored in EGTA buffer with 50% glycerol for 5-6 wk without deterioration. The isolated spindles were composed prim...

The objective was to determine the effect of three different protease inhibitors, caspase-6 specific inhibitor VEID-CHO (N-Acetyl-Val-Glu-Ile-Asp-al), calpain inhibitor leupeptin or calpain inhibitor EGTA on protein degradation, ultrastructure of myofibrils and calpain activity during postmortem (PM) aging of chicken muscle. Results showed that proteolysis of nebulin, troponin-T and desmin duri...

We have developed an immunoadsorption technique for quantitating EGTA-resistant gelsolin/actin complexes in macrophages extracted with Triton X-100. We report here that the proportion of gelsolin complexed irreversibly to actin is low in freshly harvested macrophages. The amount of the EGTA-resistant complex increases spontaneously during incubation of the cells in suspension at 37 degrees C, o...

Desmin is the main intermediate filament (IF) protein of muscle cells. In skeletal muscle, desmin IFs form a scaffold that interconnects the entire contractile apparatus with the subsarcolemmal cytoskeleton and cytoplasmic organelles. The interaction between desmin and the sarcolemma is mediated by a number of membrane proteins, many of which are Ca2+-sensitive. In the present study, we analyze...

Calcium chelators have been widely used in electrophysiological recordings of N-methyl-D-aspartate (NMDA) receptor-mediated currents, as well as in studies of excitotoxicity. Intracellularly applied calcium chelators are known to inhibit, at least in part, such calcium-dependent processes as calmodulin-dependent inactivation, calcineurin-dependent desensitization, and rundown of NMDA receptors....

The effect of 1%, 3% and 5% EGTA (ethylene glycol-bis-(beta-amino-ethyl ether) N,N,N',N'-tetra-acetic acid) on the microhardness of root dentin of the cervical third of human teeth was studied. Five newly extracted maxillary incisors were sectioned transversely at the cementoenamel junction, and the crowns were discarded. The roots were embedded in blocks of high-speed polymerized acrylic resin...

Total Ca content and that fraction of Ca sensitive to removal by the chelator ethylene glycol-bis(beta-aminoethyl ether)N,N,N',N'-tetraacetate (EGTA) have been investigated in the mouse 3T3 cell as a function of growth stage, transformation with SV40 virus, and serum levels of the media. Cells were allowed to grow through several doublings in media containing (45)Ca. The cellular content of (45...

Salt stress is one of the most serious abiotic stresses limiting plant growth and development. Calcium as an essential nutrient element important signaling molecule plays role in ameliorating adverse effect salinity on plants. This study aimed to investigate impact exogenous calcium improving salt tolerance Tartary buckwheat cultivars, cv. Xinong9920 (salt-tolerant) Xinong9909 (salt-sensitive)....

The mechanism of association of the human platelet membrane GPIIb-GPIIIa-Ca2+ complex was studied by treating solubilized membranes with various enzymes and cationic peptides and by studying the binding of “Ca2+ and 1261-fibrinogen before and after dissociation with EGTA and association with Ca2+. Neuraminidase shifted the complex cathodally (presumably due to cleavage of negatively charged dom...

washed free of EGTA and incubated for 30min at 37°C in Hepes-buffered Ringer solution (see Dormer, 1983). Amylase release was measured after centrifugation and resuspension of acini in fresh medium in the presence or absence of carbamylcholine. The secretory responses of acini swollen in the absence of EGTA were similar to those of unswollen acini. Thus, the dose-response to carbamylcholine was...