Radioiodinated Azide and Isothiocyanate Derivatives of Cocaine for Irreversible Labeling of Dopamine Transporters:  Synthesis and Covalent Binding Studies

2005 ◽  
Vol 16 (3) ◽  
pp. 644-649 ◽  
Author(s):  
John R. Lever ◽  
Mu-Fa Zou ◽  
M. Laura Parnas ◽  
Romain A. Duval ◽  
Sara E. Wirtz ◽  
...  
Keyword(s):  
Covalent Binding ◽  
Binding Studies ◽  
Dopamine Transporters ◽  
Derivatives Of

scholarly journals The binding of human complement proteins C5, factor B, β1H and properdin to complement fragment C3b on zymosan

1981 ◽  
Vol 199 (3) ◽  
pp. 485-496 ◽  
Author(s):  
R G DiScipio
Keyword(s):  
Protein Modification ◽  
Alternative Pathway ◽  
Covalent Binding ◽  
Association Constants ◽  
Affinity Constant ◽  
Distinct Region ◽  
Binding Studies ◽  
Factor B ◽  
Complement Proteins ◽  
Competition Binding

The covalent binding of complement fragment C3b to zymosan by the action of the alternative-pathway C3 convertase and the reversible binding of several complement proteins (component C5, factor B, beta 1H and properdin) to C3b on zymosan have been investigated. When C3b is deposited on zymosan after activation by a surface-bound C3 convertase, the C3b molecules are deposited in foci around the C3 convertase site, with an average of 30 C3b molecules per site. The association constants of C5, factor B, beta 1H, and properdin for C3b bound to zymosan have been determined. The association constants ranged from 6.5 x 10(-5) M-1 for factor B to 2.9 x 10(7) M-1 for properdin. An approximate stoichiometry of 1 : 1 for C5, factor B, and properdin binding to C3b has been observed. Curvilinear Scatchard plots were observed for beta 1H binding to C3b, with the maximal extrapolated ratio of beta 1H to C3b of 0.32. Physiological amounts of properdin increase by 7-fold the affinity constant for factor B binding to C3b with no alteration in the stoichiometry. Similarly, physiological amounts of factor B increase the affinity constant of properdin to C3b about 4-fold with only a small measured difference in stoichiometry. Competition binding studies and protein modification suggest that C5, factor B, beta 1H, and properdin each bind to a distinct region on C3b.

Analysis of GPIIb/IIIa receptor number by quantification of 7E3 binding to human platelets

Blood ◽  
1996 ◽  
Vol 88 (3) ◽  
pp. 907-914 ◽  
Author(s):  
CL Wagner ◽  
MA Mascelli ◽  
DS Neblock ◽  
HF Weisman ◽  
BS Coller ◽  
...  
Keyword(s):  
Quantitative Estimation ◽  
Critical Factor ◽  
Human Platelets ◽  
Single Individual ◽  
Binding Studies ◽  
Fab Fragment ◽  
High Affinity ◽  
Fibrinogen Binding ◽  
Receptor Number ◽  
Derivatives Of

Abstract A large number of glycoprotein (GP) IIb/IIIa receptors are present on the surface of platelets. Studies to define precisely the number of GPIIb/IIIa receptors using specific monoclonal antibodies (MoAbs) or fibrinogen binding have, however, yielded varying estimates of receptor number. To refine the quantitative estimation of GPIIb/IIIa receptors on resting platelets, we have used the MoAb 7E3, which has high affinity for GPIIb/IIIa. Quantitative binding studies were performed using radiolabeled conjugates of 7E3 IgG, as well as fragments and derivatives of 7E3. For platelets obtained from any single individual, the numbers of 7E3 F(ab′)2 and IgG molecules bound per platelet were equivalent (approximately 40,000), whereas the number of Fab molecules bound per platelet was consistently approximately twofold higher (approximately 80,000). To investigate the basis of the quantitative disparity in binding of intact 7E3 and 7E3 F(ab′)2 versus 7E3 Fab, we studied the binding of a newly constructed, bispecific (Fab′)2 molecule containing only a single 7E3 combining site. Because this construct bound to the same extent as the Fab species, the larger size of the intact 7E3 and 7E3 F(ab′)2 molecules could not explain the reduced number of molecules that bound per platelet compared to the Fab fragment. Rather, it appears that the valency of the antibody is the critical factor determining the number of antibody molecules bound per platelet. Thus, we conclude that the binding of 7E3 Fab corresponds most closely with surface GPIIb/IIIa number and that the number of GPIIb/IIIa receptors is approximately 80,000 per platelet.

ChemInform Abstract: Synthesis of 7-(2-Dimethylaminovinyl) Derivatives of Pyrazolo(1,5-a) pyrimidines, as Precursors of New Tricyclic Series. Binding Studies of BDZ Receptor.

ChemInform ◽  
2010 ◽  
Vol 25 (12) ◽  
pp. no-no
Author(s):  
F. BRUNI ◽  
A. COSTANZO ◽  
S. SELLERI ◽  
G. GUERRINI ◽  
L. GIUSTI ◽  
...  
Keyword(s):  
Binding Studies ◽  
Derivatives Of

scholarly journals A chemoattractant receptor on macrophages exists in two affinity states regulated by guanine nucleotides.

1984 ◽  
Vol 98 (2) ◽  
pp. 444-448 ◽  
Author(s):  
R Snyderman ◽  
M C Pike ◽  
S Edge ◽  
B Lane
Keyword(s):  
Guanine Nucleotides ◽  
Guanine Nucleotide ◽  
Cell Binding ◽  
Binding Studies ◽  
Binding Characteristics ◽  
High Affinity ◽  
Binding Data ◽  
Transduction Mechanisms ◽  
Receptor Number ◽  
Derivatives Of

The binding characteristics of the oligopeptide chemoattractant receptor on guinea pig macrophages and macrophage membrane preparations were characterized using detailed binding studies and computer analysis. Viable macrophages bound the radiolabeled chemoattractant N-formyl-methionyl-leucyl-[3H]phenylalanine with single dissociation constant (KD) of 18.4 +/- 4.6 nM with 15,300 +/- 1,800 sites per cell. Binding data from membrane preparations indicated the presence of two classes of binding sites with KD of 1.5 +/- 0.4 nM and 25.5 +/- 11.0 nM. Approximately 23% of the receptors were in the high affinity state. In the presence of added guanine nucleotide di- or triphosphates, the high affinity receptors in the membrane preparations were converted to low affinity states with no change in the total receptor number. Nonhydrolyzable derivatives of GTP were most potent in converting the receptor from its high to low affinity state. These data suggest that the affinity state of the oligopeptide chemoattractant receptor in macrophages is regulated by guanine nucleotides and GTPase, implying that the transduction mechanisms of this receptor may be controlled by a guanine nucleotide regulatory unit.

Bis-amino Acid Derivatives of 1,1′-Ferrocenedicarboxylic Acid: Structural, Electrochemical, and Metal Ion Binding Studies

2014 ◽  
Vol 33 (18) ◽  
pp. 4873-4887 ◽  
Author(s):  
Bimalendu Adhikari ◽  
Alan J. Lough ◽  
Bryan Barker ◽  
Afzal Shah ◽  
Cuili Xiang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Metal Ion ◽  
Amino Acid Derivatives ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Binding Studies ◽  
Derivatives Of

scholarly journals Dirhenium(III) complex with beta-alanine ligand: anticancer, antioxidant and DNA-binding properties

2020 ◽  
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Tumor Growth ◽  
Electronic Absorption Spectra ◽  
Covalent Binding ◽  
Binding Constants ◽  
Free Form ◽  
Amino Acid Derivatives ◽  
Ct Dna ◽  
Derivatives Of

Earlier we have shown that dirhenium(III) dicarboxylate complex with γ-aminobutyric acid possessed higher antitumor activity, than those of the previously investigated alkylcarboxylates, also may act as a modulator of cisplatin mechanism of action and as a stabilizer of red blood cells in tumor-bearing organisms. Thus, the task of the work was to investigate anticancer activity of the complex cis-[Re2(β-Ala)2Cl6] (I) in the model of tumor growth in vivo and to realize if the amino acid residue influences the DNA-binding activity of the amino acid derivatives of the cluster rhenium(III) compounds. Antitumor properties of the complex I were studied in the model of tumor growth with the use of Wistar rats inoculated by tumor carcinoma Guerink cells. The introduction of the compound alone in free and liposomal forms inhibited the tumor growth by 36 % and 45 % correspondingly, that is more than for dirhenium(III) clusters with alkyl ligands. The combined introduction of I and cisplatin had a significant impact on the tumor growth and showed the disappearance of the tumors in most of the animals. No considerable differences were found between introduction of liposomal and free form of I. The electronic absorption spectra of Calf Thymus DNA (CT-DNA) exhibit hyperchromism in the presence of increasing amounts of I. The DNA band at ~ 260 nm arises from the π-π* transitions of the nucleic acid bases and changes in the intensity and slight wavelength shifts of this characteristic band reflect the corresponding structural modifications of the DNA, which include changes in stacking, disruption of the hydrogen bonds between complementary strands, covalent binding of the DNA bases, intercalation of aromatic rings and others. The binding constant Kb(I) = 2.43 × 103 M-1 to CT-DNA was obtained that was lower than the values reported for the classical DNA intercalators and compares well with the magnitude of the binding constants for other complexes of dirhenium(III); titration of СT-DNA with cisPt and hydrogen peroxide also leads to a hypochromic effect, weak at low concentrations and more significant at high concentrations of I; the DNA binding constants increased in several times when using H2O2 or cisplatin that confirms a mechanism for redox activation of interaction of I with DNA in a cancer cell. The obtained results demonstrate the possibility of application of the amino acid derivatives of dirhenium(III) clusters in antitumor therapy.

Water-soluble poly(acrylamide-allylamine) derivatives of saccharides for protein-saccharide binding studies

1995 ◽  
Vol 12 (1) ◽  
pp. 51-54 ◽  
Author(s):  
J. Klein ◽  
M. Kraus ◽  
M. Tich� ◽  
B. Zelezn� ◽  
V. Jon�kov� ◽  
...  
Keyword(s):  
Water Soluble ◽  
Binding Studies ◽  
Saccharide Binding ◽  
Derivatives Of ◽  
Soluble Poly ◽  
Poly Acrylamide
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