Calcium activation

Factor XIII. Factor XIII circulates in the blood as a zymogen composed of two pairs of different polypeptide chains designated A and B. Inert Factor XIII has a molecular weight of 350,000 daltons and is converted to its active transglutaminase form in the presence of thrombin and calcium. Activated Factor XIII, Xllla, induces an irreversible amide exchange reaction between the y-glutamine and S-lysine side chains of adjacent fibrin... 

Bondar, V. S., Vysotskii, E. S., Gamalei, I. A., and Kaulin, A. B. (1991). Isolation, properties, and application of calcium activated photoprotein from the hydroid polyp Obelia longissima. Tsitologiya 33 50-59. 

Campbell, A. K. (1974). Extraction, partial purification and properties of obelin, the calcium-activated luminescent protein from the hydroid Obelia geniculata. Biochem. J. 143 411—418. 

Campbell, A. K., Patel, A. K., Razavi, Z. S., and McCapra, F. (1988). Formation of the calcium-activated photoprotein obelin from apo-obelin and mRNA inside human neutrophils. Biochem. J. 252 143-149. 

Cormier, M. J., Prasher, D. C., Longinaru, M., and McCann, R. O. (1989). The enzymology and molecular biology of the calcium-activated photoprotein, aequorin. Photochem. Photobiol. 49 509-512. 

Gitelzon, G. I., Tugai, V. A., and Zakharchenko, A. N. (1990). Production of obelin, a calcium-activated photoprotein, from Obelia longissima and its application for registration of the calcium efflux from the fragmented sarcoplasmic reticulum of skeletal muscles. Ukr. Biokhim. Zh. 62 69-76. 

Hastings, J. W., and Morin, J. G. (1968). Calcium activated bioluminescent protein from ctenophores (Mnemiopsis) and colonial hydroids (Obelia). Biol. Bull. 135 422. 

Illarionov, B. A., et al. (1992). Cloning and expression of cDNA coding for the calcium-activated photoprotein obelin from the hydroid polyp Obelia longissima. Dokl. Akad. Nauk SSSR 326 911-913. 

Vysotskii, E. S., et al. (1990). Extraction, some properties and application of obelin, calcium-activated photoprotein. In Jezowska-Trzebiatowska, B. (ed.), Biol. Lumin., Proc. Int. Sch., 1st, 1989, pp. 386-395. World Scientific, Singapore. 

Vysotski, E. S., Bondar, V. S., Trofimov, K. P., and Gitelzon, I. I. (1991). Luminescence of the calcium-activated photoprotein obelin under the action of active forms of oxygen. Dokl. Akad. Nauk SSSR 321 850-854. 

Ward, W. W., and Seliger, H. H. (1974a). Extraction and purification of calcium-activated photoproteins from ctenophores. Biochemistry 13 1491-1499. 

Cardiac IKi is the major K+ current responsible for stabilizing the resting membranepotential and shaping the late phase of repolarization of the action potential in cardiac myocytes. The name should not be confused with that of an Intermediate conductance calcium-activated K+ channel, which sometimes is also called IK1. 

Calcium activities as low as 5 x 10 7 M can be measured, with selectivity coefficients ACaMg and ACaK of 0.02 and 0.001, respectively. Such potential response is independent of the pH over the pH range from 5.5 to 11.0. Above pH 11, Ca(OH)+ is formed, while below pH 5.5, protons interfere. Because of its attractive response characteristics, the calcium ISE has proved to be a valuable tool for the determination of calcium ion activity in various biological fluids. 

Figure 2. Reporting of cytosolic free calcium levels by indo-1. Increases in cytosolic calcium, due either to entry of extracellular calcium via calcium channels or to release of intracellular calcium sequestered in organelles such as smooth endoplasmic reticulum, results in formation of the indo-l-calcium complex. Fluorescence intensity at 400 nm (excitation at 340 nm) is proportional to the concentration of this complex the dissociation constant for this complex is about 250 nff (24), making this probe useful for detecting calcium activities in the range of 25 to 2500 nJ. ...

Vennekens R, Olausson J, Meissner M, Bloch W, Mathar I, Philipp SE, Schmitz F, Weissgerber R Nilius B, Flockerzi V, Freichel M Increased IgE-dependent mast cell activation and anaphylactic responses in mice lacking the calcium-activated nonselective cation channel XRPM4. Nat Immunol 2007 8 312-320. Guo Z, Xurner C, Castle D Relocation of the t-SNARE SNAP-23 from lamellipodia-like cell surface projections regulates compound exocytosis in mast cells. Cell 1998 94 537-548. 

Vergara, C, Latorre, R, Marrion, NV and Adelman, JP (1998) Calcium-activated potassium channels. Curr. Op. Neurobiol. 8 321-329. 

Jackson, M.J., Jones, D.A. and Edwards, RH.T. (1984). Experimental skeletal muscle damage the nature of the calcium-activated degenerative processes. Eur. J. Clin. Invest. 14, 369-374. 

During ischaemia, NOS is activated by calcium influx or by cytokines like tumour necrosis factor (TNF) or by lipopolysaccharide (LPS) and NO is produced in excess. It has been proposed that the excitotoxic effect of glutamate, which contributes to ischaemia-induced neuronal damage, is mediated by increased production of NO via a chain of events that includes increases in intracellular calcium (via glutamate activation of NMDA receptors), calcium activation of NOS, production of NO and peroxynitrite, and induction of lipid peroxidation. In fact, N-nitro-L-atginine, a selective inhibitor of NOS, has been shown to prevent glutamate-induced neurotoxicity in cortical cell cultures (Dawson rf /., 1991). 

Wendt, I. and Stephenson, D., Effects of caffeine on calcium-activated force production in skinned cardiac and skeletal muscle fibers of the rat, European Journal of Physiology, 398, 210, 1983. 

Simon, S. M. and Llinas, R. R. Compartmentalization of the submembrane calcium activity during calcium influx and its significance in transmitter release. Biophys. J. 48 485-198, 1985. 

The characteristics of the four major classes of histamine receptors are summarized. Question marks indicate suggestions from the literature that have not been confirmed. AA, arachidonic acid DAG, diacylglycerol Iko,2+, calcium-activated potassium current IP3, inositol 1,4,5-trisphosphate NHE, sodium-proton exchange, PKC, protein kinase C NO, nitric oxide PTPLC, phosphoinositide-specific phospholipase C TXA2, thromboxane A2. Has brain-penetrating characteristics after systemic administration. 

Fig. 4.1. Cellular model illustrating cell types in vascular wall involved in vasorelaxation induced by SERMs. Putative targets of SERMs are indicated within cyan tags. SERMs directly affect L-type VDCC, BK fil subunit in smooth muscle cells, and ER in endothelial cells. L-type VDCC L-type voltage-dependent calcium channel BK calcium-activated large conductance K+ channel PKG protein kinase G eNOS endothelial nitric oxide synthase GC soluble guanylate cyclase cGMP cyclic GM P V electrochemical membrane potential ER estrogen receptor. See text for further details...

Dick GM, Hunter AC, Sanders KM (2002) Ethylbromide tamoxifen, a membrane-impermeant antiestrogen, activates smooth muscle calcium-activated large-conductance potassium channels from the extracellular side. Mol Pharmacol 61 (5) 1105—1113... 

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