Synthesis of conjugates of 5-halouracils with proteins using activated esters

1979 ◽  
Vol 44 (5) ◽  
pp. 1634-1641 ◽  
Author(s):  
Helmut Pischel ◽  
Antonín Holý ◽  
Günther Wagner
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Aminocaproic Acid ◽  
Protein Molecule ◽  
Activated Esters ◽  
High Yields ◽  
Uracil Derivative

1-Carboxymethyluracil (Ia) and its 5-fluoro (Ib), 5-bromo (Ic) and 5-iodo (Id) derivatives were transformed into the p-nitrophenyl esters IIa-IId by reaction with p-nitrophenol in the presence of N,N'-dicyclohexylcarbodiimide. Reaction of these compounds with ammonia or ε-aminocaproic acid afforded the corresponding 1-aminocarbonylmethyluracil (IIIa-d) and 1-N-(5-carboxypentyl)aminocarbonylmethyluracil (IVa-d) derivatives. Reaction of compounds II with human serum albumin and bovine γ-globulin at pH 9.2 gave high yields of conjugates of the type V and VI, respectively, containing 10-50 uracil derivative moieties bound to the protein molecule.

Synthesis of conjugates of 1-(carboxymethyl)cytosine and 1-(5-O-carboxymethyl-β-D-arabinofuranosyl)cytosine with proteins

1979 ◽  
Vol 44 (10) ◽  
pp. 3023-3032 ◽  
Author(s):  
Helmut Pischel ◽  
Antonín Holý ◽  
Günther Wagner
Keyword(s):  
Human Serum Albumin ◽  
Acetic Anhydride ◽  
Serum Albumin ◽  
Human Serum ◽  
Activated Esters ◽  
Hydrolysis Of

1-(Carboxymethyl)cytosine (Ia), 1-(5-O-carboxymethyl-β-D-arabinofuranosyl)cytosine (IIa) and 5'-O-carboxylmethylcytidine (IIIa) were transformed by treatment with acetic anhydride and 4-dimethylaminopyridine to the peracetyl derivatives Ib-IIIb. These products reacted with p-nitrophenol in the presence of N, N'-dicyclohexylcarbodiimide to give the activated esters Ic-IIIc which on reaction with ammonia, dimethylamine or 2-aminoethanol afforded the corresponding carboxamides Id-IIId, IIe,f. Reactions of Ic and IIc with human serum albumin and bovine γ-globulin at pH 9.2, followed by hydrolysis of the N- or O-acetyl groups at pH 9.5, gave 50% up to 64% yields of the respective conjugates Ig, IIg and Ih, IIh.

Calcium ion binding to clinically relevant chemical modifications of human serum albumin

1995 ◽  
Vol 41 (11) ◽  
pp. 1654-1661 ◽  
Author(s):  
H Vorum ◽  
K Fisker ◽  
M Otagiri ◽  
A O Pedersen ◽  
U Kragh-Hansen
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Conformational Changes ◽  
Calcium Binding ◽  
Equilibrium Dialysis ◽  
Thiol Group ◽  
Protein Molecule ◽  
Penicillin G ◽  
Lysine Residues

Abstract Calcium binding to glycated, penicilloylated, acetylated, and normal defatted human serum albumin as well as to mercapt- and nonmercaptalbumin was studied by equilibrium dialysis of radioactive Ca2+. Binding was quantified by five Scatchard constants [ni = 1, (i = 1-4) and n5 = 10]. Glycation resulted in increased k1- and k2-values and unchanged k3-k5-values, whereas penicilloylation increased all five association constants. The increments were greater the more pronounced the modification, and the enhancements caused by penicilloylation were, for the same degree of modification, greater than those produced by glycation. In contrast, acetylation by acetylsalicylate did not affect calcium binding. Likewise, binding to mercapt- and nonmercaptalbumin was the same, a finding showing that the thiol group of cysteine 34 is not important for calcium binding. D-Glucose and penicillin G are known to react with lysine residues of albumin, and the enhancement of binding resulting from glycation or penicilloylation is probably brought about by unspecific electrostatic effects, possibly supplemented by conformational changes of the protein molecule. The relative importance of the three domains of human serum albumin for calcium binding is discussed.

scholarly journals 4-Hydroxycoumarin Derivative:N-(diphenylmethyl)-2-[(2-oxo-2H-chromen-4-yl)oxy]acetamide Interaction with Human Serum Albumin

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Shanmugavel Chinnathambi ◽  
Subramani Karthikeyan ◽  
Mangaiyarkarsi Rajendiran ◽  
Kanniyappan Udayakumar ◽  
Arunkumar Manoharan ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Active Sites ◽  
Entropy Change ◽  
Protein Molecule ◽  
Coumarin Derivative ◽  
Biologically Active ◽  
Computational Technique ◽  
Distribution Analysis

In this study, the interaction between the coumarin derivative:N-(diphenylmethyl)-2-[(2-oxo-2H-chromen-4-yl)oxy]acetamide, biologically active drug, and human serum albumin (HSA) was investigated by using various optical spectroscopy techniques along with the computational technique. The results of steady-state fluorescence spectroscopy show that the static quenching occurred while increasing the coumarin drug concentration into HSA. Also, the binding constant (K) and thermodynamical parameters of enthalpy change (ΔH°), entropy change (ΔS°), and Gibbs free energy change (ΔG°) were calculated at different temperatures (293 K, 298 K, and 303 K). The results are in good agreement with those of molecular docking studies, and also, the docking study was carried out to understand the hydrogen bonding and hydrophobic interaction between human serum albumin and coumarin derivative. In addition to the docking, charge distribution analysis was done to understand the internal stability of coumarin derivative active sites of human serum albumin. Further time-resolved emission spectroscopy (TRES) studies were carried out between free HSA and HSA-coumarin complex, and the result confirms the presence of the drug in the protein molecule without cytotoxicity.

scholarly journals Deuteroporphyrin-albumin binding equilibrium. The effects of porphyrin self-aggregation studied for the human and the bovine proteins

1985 ◽  
Vol 229 (1) ◽  
pp. 197-203 ◽  
Author(s):  
M Rotenberg ◽  
R Margalit
Keyword(s):  
Human Serum Albumin ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Bovine Serum ◽  
Binding Constants ◽  
Protein Molecule ◽  
Competitive Model ◽  
Phosphate Buffered Saline ◽  
Self Aggregation

The binding equilibrium of deuteroporphyrin IX to human serum albumin and to bovine serum albumin was studied, by monitoring protein-induced changes in the porphyrin fluorescence and taking into consideration the self-aggregation of the porphyrin. To have control over the latter, the range of porphyrin concentrations was chosen to maker dimers (non-covalent) the dominant aggregate. Each protein was found to have one high-affinity site for deuteroporphyrin IX monomers, the magnitudes of the equilibrium binding constants (25 degrees C, neutral pH, phosphate-buffered saline) being 4.5 (+/- 1.5) X 10(7) M-1 and 1.7 (+/- 0.2) X 10(6) M-1 for human serum albumin and for bovine serum albumin respectively. Deuteroporphyrin IX dimers were found to bind directly to the protein, each protein binding one dimer, with high affinity. Two models are proposed for the protein-binding of porphyrin monomers and dimers in a porphyrin system having both species: a competitive model, where each protein molecule has only one binding site, which can be occupied by either a monomer or a dimer; a non-competitive model, where each protein molecule has two binding sites, one for monomers and one for dimers. On testing the fit of the data to the models, an argument can be made to favour the non-competitive model, the equilibrium binding constants of the dimers, for the non-competitive model (25 degrees C, neutral pH, phosphate-buffered saline), being: 8.0 (+/- 1.8) X 10(8) M-1 and 1.2 (+/- 0.6) X 10(7) M-1 for human serum albumin and bovine serum albumin respectively.

Gradual exposure of cystine side-chain residues during urea denaturation of human serum albumin

1981 ◽  
Vol 46 (1) ◽  
pp. 48-51 ◽  
Author(s):  
Josef Chmelík ◽  
Jiří Kadleček ◽  
Vítěz Kalous
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Conformational Changes ◽  
Protein Molecule ◽  
Side Chain ◽  
Urea Denaturation ◽  
Catalytic Hydrogen ◽  
Denaturation Curve

Showing the accessibility of disulfide groups in the protein molecule, the polarographic catalytic hydrogen current (Brdicka current) was employed for the investigation of the urea denaturation of human serum albumin. The stepwise character of the denaturation curve was accounted for the gradual conformational changes of the protein molecule and related increasing accessibility of cystine side-chain residues.

II. Lokalisation der Placenta mit 113Inm- Human-Serum-Albumin

1969 ◽  
Vol 08 (01) ◽  
pp. 15-21 ◽  
Author(s):  
K. E. Scheer ◽  
J. Heep ◽  
W. Maier-Borst ◽  
W. J. Lorenz ◽  
H. Sinn ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Vena Cava ◽  
Placenta Praevia ◽  
Wird Eine

ZusammenfassungNach tierexperimentellen Voruntersuchungen wurde die Placentographie mit trägerfreiem 113Inm -HSA als klinische Methode eingeführt. Vor Amniocentesen und bei Verdacht auf Placenta praevia werden Placentographien geschrieben. Den Schwangeren wird eine Aktivität von 500 μCi in die Cubitalvene injiziert. Die der Aktivität entsprechende Indiummenge ist kleiner als 0,1 ng. Die fetale Strahlenbelastung liegt unter lOmrad. Bei Anwendung von 113Inm-HSA entfällt eine Blockade der mütterlichen und fetalen Schilddrüsen. Die genaue Abgrenzung einer Placenta praevia wird nicht durch eine Blasenaktivität beeinträchtigt.Es wurden bisher 19 Placentalokalisationen durchgeführt. In allen Fällen konnte der Placentasitz eindeutig festgestellt werden. Bedingt durch die lange Liegezeit beim Aufnehmen eines Szintigramms kam es in zwei Fällen zu einem Vena-Cava-Kompressions-Syndrom. Zur Verhinderung dieser klinischen Zwischenfälle werden inzwischen Placentographien mit der Anger-Kamera aufgenommen. Mit Hilfe des divergierenden Kollimators konnte der gesamte Abdominalbereich erfaßt werden. Die Aufnahmezeit konnte auf 7 — 10 Minuten verkürzt werden. Die intravenöse injizierte Aktivität betrug bei dieser Methode ebenfalls 500 μCi. Der diagnostische Aussagewert der Kamerabilder ist szintigraphischen Aufnahmen gleichwertig.

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