Binding sites solubilization

Burch, R., Mais, D., Pepkowitz, S. and Halushka, P. (1985). Hydrodynamic properties of a thromboxane A2/prostaglandin H2 antagonist binding site solubilized from human platelets. Biochem. Biophys. Res. Commun., 132, 961—968... 

Chemical modification studies with fluorescein-5 -isothiocyanate support the proximity of Lys515 to the ATP binding site [98,113-117,212,339]. Fluorescein-5 -isothiocyanate stoichiometrically reacts with the Ca -ATPase in intact or solubilized sarcoplasmic reticulum at a mildly alkaline pH, causing inhibition of ATPase activity, ATP-dependent Ca transport, and the phosphorylation of the Ca " -ATPase by ATP the Ca uptake energized by acetylphosphate, carbamylphos-phate or j -nitrophenyl phosphate is only partially inhibited [113,114,212,339]. The reaction of -ATPase with FITC is competitively inhibited by ATP, AMPPNP, TNP-ATP, and less effectively by ADP or ITP the concentrations of the various nucleotides required for protection are consistent with their affinities for the ATP binding site of the Ca -ATPase [114,212,340]. 

Chemical modifications like alkylation with (A-ethylmaleimide (NEM) or oxidation with diamide that inhibit the phosphorylation activity of the enzyme did not seem to have any significant effect on the high affinity binding site when the enzyme was solubilized in the detergent decyl-PEG [69,41]. However, in the intact membrane these treatments reduced the affinity by a factor of 2-3. The reduction of the affinity was exclusively due to modification of the cysteine residue at position 384 in the B domain [69]. Apparently, the detergent effects the interaction between the B and C domains. 

Fig. 10. Mechanisms of steady-slqte kinetics of sugar phosphorylation catalyzed by E-IIs in a non-compartmentalized system. (A) The R. sphaeroides 11 model. The model is based on the kinetic data discussed in the text. Only one kinetic route leads to phosphorylation of fructose. (B) The E. coli ll " model. The model in Fig. 8 was translated into a kinetic scheme that would describe mannitol phosphorylation catalyzed by Il solubilized in detergent. Two kinetic routes lead to phosphorylation of mannitol. Mannitol can bind either to state EPcy, or EPpe,. E represents the complex of SF (soluble factor) and 11 and II in A and B, respectively. EP represents the phosphorylated states of the E-IIs. Subscripts cyt and per denote the orientation of the sugar binding site to the cytoplasm and periplasm, respectively. PEP, phosphoenolpyruvate.

Krueger, B.K. Ratzlaff, R.W. Strichartz, G.R. and Blaustein, M.P. Saxitoxin binding to synaptosomes, membranes and solubilized binding sites from rat brain. J. Membr Biol 50 287-310,... 

In the classical photoaffinity experiment a tissue homogenate is solubilized by standard detergents and incubated with the radiolabeled photoprobe for non-covalent binding prior to irradiation. By illumination at the excitation wavelength a covalent linkage is established between the ligand and receptor around the binding site as shown in Scheme 2. 

Facklam, M. and Bowery, N. G. (1993) Solubilization and characterization of GABAb receptor binding sites from porcine brain synaptic membranes. Br. J. Pharmacol. 110, 1291-1296. 

Fath A, Boiler T. Solubilization, partial purification and characterization of a binding site for a gly copeptide elicitor from microsomal membranes of tomato cells. Plant Physiol 1996 112 1659-1668. 

An alternative mechanism for loss of membrane integrity is via the solubilization of phospholipids by thionins." This revised version of the carpet model is based on the observation of a conserved binding site for phospholipids head groups in thionins, their tendency to form oligomers," " and small-angle X-ray scattering... 

The proximal calcium binding site is coupled to the heme group by virtue of the fact that one of its ligands, Thrl71, is adjacent to the proximal histidine residue, Hisl70 (Fig. 4). The results of site-directed mutagenesis studies at this position are awaited with interest. An illustration of the importance of both calcium sites to the structure and function of HRP C is afforded by the need to incorporate calcium as a component of in vitro folding mixtures to obtain active recombinant enzyme from solubilized inclusion bodies (64). 

Oliveira JC, Sebastiao AM, Ribeiro JA (1991) Solubilized rat brain adenosine receptors have two high-affinity binding sites for l,3-dipropyl-8-cyclopentylxanthine. J Neurochem 57(4) 1165—1171 Palmer TM, Benovic JL, Stiles GL (1995) Agonist-dependent phosphorylation and desensitization of the rat A3 adenosine receptor. Evidence for a G-protein-coupled receptor kinase-mediated mechanism. J Biol Chem 270(49) 29607-29613... 

Venis, M. (1977). Solubilization and partial purification of auxin-binding sites of com membranes. Nature (London) 266, 268-269. 

Simon EJ, Hiller JM. Solubilization and Purification of opioid binding sites. In Pasternak GW, ed. The Opiate Receptors. Clifton, NJ Humana Press, 1988 165-194. 

The solubilized Fi has the active sites of the entire enzyme and catalyzes ATP hydrolysis. Similar to mitochondrial Fi,42) K coli Fi has six nucleotide binding sites (three for catalytic and three for non-catalytic sites).43) The role(s) of the non-catalytic sites is still unknown. The . coli Fi having at least two vacant catalytic sites, or Fi having less than one vacant catalytic site could be prepared.44 ... 

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