Direct experimental verification of applicability of single-site model for angle integrated photoemission of small TK concentrated Ce compounds

Abstract Recently, a single-site stochastic precipitation model called “the mixture of generalized chain-dependent processes conditioned on a climate variable” was developed. The model can effectively eliminate overdispersion—that is, underestimation in variance of seasonal precipitation total. In this paper, the single-site model is further developed into a multisite stochastic precipitation model by driving a collection of individual single-site models, but with spatial dependence following a method proposed by D. S. Wilks. Specifically, a computationally effective algorithm for estimating the spatial dependence of precipitation occurrence is developed to replace the construction of the empirical curves in the Wilks method. An effective and straightforward approach for correcting the bias of the spatial correlation of precipitation intensity is also proposed. This model is tested on a small network of sites from a significant hydroelectric power generation region of South Island, New Zealand.

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Spin-rotational-invariant theory of transition-metal magnetism at finite temperatures: Systematic study of a single-site model

Physical Review B ◽

10.1103/physrevb.93.214435 ◽

2016 ◽

Vol 93 (21) ◽

Author(s):

G. M. Pastor ◽

J. Dorantes-Dávila

Keyword(s):

Transition Metal ◽

Systematic Study ◽

Invariant Theory ◽

Single Site ◽

Site Model ◽

Rotational Invariant

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Drug inhibition indicates a single-site model of the 5-HT uptake site/antidepressant binding site in rat and human brain

Psychopharmacology ◽

10.1007/bf00634446 ◽

1989 ◽

Vol 99 (1) ◽

pp. 17-21 ◽

Cited By ~ 12

Author(s):

Jan O. Marcusson ◽

Anna Andersson ◽

Inger B�ckstr�m

Keyword(s):

Human Brain ◽

Binding Site ◽

Single Site ◽

Site Model ◽

Drug Inhibition ◽

5 Ht Uptake

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All human Na+-K+-ATPase α-subunit isoforms have a similar affinity for cardiac glycosides

AJP Cell Physiology ◽

10.1152/ajpcell.2001.281.4.c1336 ◽

2001 ◽

Vol 281 (4) ◽

pp. C1336-C1343 ◽

Cited By ~ 59

Author(s):

Jiangnan Wang ◽

Jeffrey B. Velotta ◽

Alicia A. McDonough ◽

Robert A. Farley

Keyword(s):

Rate Constants ◽

Binding Sites ◽

Human Heart ◽

Cardiac Glycosides ◽

Selective Inhibition ◽

Single Site ◽

Human Tissues ◽

Α Subunit ◽

Site Model ◽

Subunit Isoforms

Three α-subunit isoforms of the sodium pump, which is the receptor for cardiac glycosides, are expressed in human heart. The aim of this study was to determine whether these isoforms have distinct affinities for the cardiac glycoside ouabain. Equilibrium ouabain binding to membranes from a panel of different human tissues and cell lines derived from human tissues was compared by an F statistic to determine whether a single population of binding sites or two populations of sites with different affinities would better fit the data. For all tissues, the single-site model fit the data as well as the two-site model. The mean equilibrium dissociation constant ( K d) for all samples calculated using the single-site model was 18 ± 6 nM (mean ± SD). No difference in K d was found between nonfailing and failing human heart samples, although the maximum number of binding sites in failing heart was only ∼50% of the number of sites in nonfailing heart. Measurement of association rate constants and dissociation rate constants confirmed that the binding affinities of the different human α-isoforms are similar to each other, although calculated K d values were lower than those determined by equilibrium binding. These results indicate both that the affinity of all human α-subunit isoforms for ouabain is similar and that the increased sensitivity of failing human heart to cardiac glycosides is probably due to a reduction in the number of pumps in the heart rather than to a selective inhibition of a subset of pumps with different affinities for the drugs.

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The Interaction of Soluble Phospholipids with Coagulation Factor VIIa

Blood ◽

10.1182/blood.v116.21.4421.4421 ◽

2010 ◽

Vol 116 (21) ◽

pp. 4421-4421

Author(s):

Tanusree Sengupta ◽

Rinku Majumder ◽

Barry R. Lentz

Keyword(s):

Conflicts Of Interest ◽

Factor Viia ◽

Coagulation Factor ◽

Current Data ◽

Single Site ◽

Coagulation Cascade ◽

Site Model ◽

Weak Site ◽

Vitro Model

Abstract Abstract 4421 Factor VIIa (fVIIa) is one of the key proteins in the blood coagulation cascade. It activates factors IX and × on a negatively charged phospholipid surface in either a TF-dependent or TF-independent fashion (Silverberg et al, 1977; Bom et al, 1990). Monroe et al (1997) demonstrated that fVIIa binds to activated platelets independent of TF and partially restores thrombin generation in an in vitro model of hemophilia. Thus, it appears that interaction of fVIIa with platelet phospholipids plays an important role. We report that binding of 1,2-dihexanoyl-sn-glycero-3-phospholipids -L-serine (C6PS) and 1,2-dihexanoyl-sn-glycero-3-phosphoethanolamine (C6PE) to fVIIa causes changes in its activity as well as structure. Titration with C6PS led to changes in intrinsic fluorescence indicative of two or more binding sites for this lipid. Similar titrations with C6PE indicated that it probably binds to a single site on the protein. Experiments are underway to test this initial conclusion. Both lipids bind with comparable affinity (kd ~ 165 and 160 μ M) when data were analyzed using a single site model. We also examined the effect of the soluble lipids on the activity of fVIIa. Both C6PS and C6PE binding increased fVIIa proteolytic and amidolytic activity, with the effect of C6PS being more pronounced. Based on current data, it appears that both lipids bind to a single weak site, but that binding of either to this site promotes binding of C6PS to a second, tighter, and C6PS-specific site, which seems to be crucial in regulating activity. Further experiments are underway to test this hypothesis. Disclosures: No relevant conflicts of interest to declare.

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Identification of CCK-A receptors on chief cells with use of a novel, highly selective ligand

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1995.268.4.g605 ◽

1995 ◽

Vol 268 (4) ◽

pp. G605-G612 ◽

Cited By ~ 1

Author(s):

T. K. Pradhan ◽

J. M. Qian ◽

V. E. Sutliff ◽

S. A. Mantey ◽

R. T. Jensen

Keyword(s):

Biological Activity ◽

Guinea Pig ◽

Single Site ◽

Chief Cells ◽

Functional Studies ◽

Site Model ◽

Selective Ligand ◽

Receptor Number ◽

Cck Antagonists ◽

First Time

Functional studies suggest that guinea pig chief cells have both cholecystokinin-A (CCK-A) and CCK-B receptors (CCK-A-R and CCK-B-R, respectively). However, all efforts to directly characterize the specific CCK-A-R using binding have been unsuccessful. Recent studies describe specific CCK-A-R agonists such as A-71378 ([desamino-Nle28,31-(N-methyl)Asp32]CCK heptapeptide]. In the present study, [D-Tyr-Gly]A-71378 was synthesized, which has > 300-fold selectivity for CCK-A-R and can be iodinated. [D-Tyr-Gly]A-71378 was equipotent to A-71378 in stimulating pepsinogen release from purified guinea pig chief cells. Binding of 125I-labeled [D-Tyr-Gly]A-71378 was saturable and specific. Potencies for inhibiting binding were as follows: [D-Tyr-Gly]A-71378 = A-71378 = 4x CCK octapeptide (CCK-8) > 1,000x des(SO4)-CCK-8, gastrin. In contrast, for 125I-gastrin binding they were CCK-8 > gastrin-17-I > des(SO4)-CCK-8 >> A-71378 or [D-Tyr-Gly]A-71378. Binding of [D-Tyr-Gly]A-71378 was best fitted by a two-site model. In contrast, 125I-gastrin binding was fitted with a single-site model. For inhibiting binding of 125I-[D-Tyr-Gly]A-71378, the CCK antagonists had relative affinities of L-364,718 >> L-365,260, and the reverse was true with 125I-gastrin. Correlation of binding with changes in biological activity suggested low-affinity CCK-A-R were mediating these changes. These results demonstrate directly for the first time that guinea pig chief cells possess CCK-A-R and CCK-B-R. The pharmacology of these CCK-A-R resembles those on other tissues. This novel, highly selective CCK-A ligand should be useful because it will identify CCK-A-R when they make up as little as 0.2% of the total CCK receptor number.

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