Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rabbits treated daily and for seven consecutive days with 6-mercaptopurine bovine gamma globulin conjugates (MPI--n-BGG; 'I'--characterizes the king of chemical binding and 'n' the number of coupled MP-residues per one mole BGG) show an altered immunological reactivity. A following intradermal immunization with BGG alum adsorbate results in a suppressed anti BGG antibody production on the third day after antigen application (antibody titer 1:320, antibody titer of control animals--pretreated with BGG and uncoupled 6-MP equals 1:5120). Already three days later the antibody titers of the test groups show a significant increase and are two dilution stages higher than the titers of the controls. A suppressive effect on the third day is induced by MPI--13-BGG, MPI--26-BGG, MPI--36-BGG and MPI--46-BGG; the later adjuvant effect can only be seen in the MPI--26-BGG, MPI--36-BGG and MPI--46-BGG but not in the MPI--13-BGG pretreated animal group. While the short time suppression was antigen specific--the humoral immune response against a second unrelated antigen was not reduced--the adjuvans effect was not antigen specific. A pretreatment with the substances mentioned above results in an increased anti BGG and anti HSA serum antibody level. Comparing investigations on the unspecific immunosuppression in rabbits by 6-mercaptopurine shows that application of 10 mg 6-MP/kg/day for seven days at first leads to a suppression but later on to an enhancement of antibody production. Application of 10 mg 6-MP/kg/day for 10 days results in a long lasting suppression without enhancement effect. As a reason for these differences the different catabolism of immunosuppressive agent and antigen is discussed. For the phenomena following antigen specific immunosuppression, similar mechanisms can be responsible.
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PMID:[Modification of immune reactions by antigen-immunosuppressive agent conjugates. V. Studies on antigen-specific activity of 6-mercaptopurine bovine gamma globulin conjugates on the humoral immune response in rabbits]. 7 98

Two fragments were isolated from BSA one was derived from the first terminal third of the molecule and the second from the last third of the molecule. Each fragment inhibited the reaction of BSA-anti BSA by 90% or better. An immunoabsorbent of each bound 90% of anti BSA. Each fragment bound two antibody molecules per mole of fragment. These results are explained by the concept that BSA contains repeating identical or similar antigenic determinants. Conformational non identity of various batches of BSA was revealed by reactivity of the disulfide bonds at the neutral transition. Trypsin was found to cleave GSA, PSA, and HSA to yield an immunochemically reactive fragment. At least in the case of HSA, the fragment exhibited all the immunochemical reactivity of the native protein.
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PMID:Immunochemistry of bovine serum albumin. 8 78

Galactosyl-neoglycoalbumin (NGA) is a synthetic ligand to the hepatocyte-specific receptor, hepatic binding protein. In-vitro and in-vivo characterization of a chelation-based derivative of NGA, deferoxamine-galactosyl-neoglycoalbumin (DF-NGA), is described. A two-step glutaraldehyde method was used to covalently couple deferoxamine (DF) to NGA. Products with an average DF-to-NGA ratio of less than 2 contained less than 3% polymeric DF-NGA. All products retained the chelator after 12 mo of storage at 4 degrees C. Gallium labeling of DF-NGA-41 (41 galactose units per HSA) with an average of 1.1 DF per NGA was quantitative within 15 min after the addition of 67Ga-citrate. The labeled product was stable for at least 24 hr. Scatchard and reverse-binding assays of 67Ga-DF-NGA-41 revealed a forward binding rate constant kb similar to that of 125I-NGA-44. The %ID of 67Ga-DF-NGA-41 in rabbit liver was approximately 90% at 10 min after injection of 1.2 x 10(-9) mole DF-NGA per kilogram of body weight. This value decreased to 40% at a scaled molar dose of 1.2 x 10(-7) mol/kg. Biodistribution data of 67Ga-DF-NGA in rabbits was similar to 99mTc-NGA. High tissue specificity and facile labeling will make 68Ga-labeled neoglycoalbumin an ideal agent for regional measurements of receptor biochemistry in the investigational and clinical setting.
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PMID:Gallium-labeled deferoxamine-galactosyl-neoglycoalbumin: a radiopharmaceutical for regional measurement of hepatic receptor biochemistry. 159 32

Pigment-protein complexes of chlorin e6 (Chl e6) with human (HSA) and bovine serum albumines (BSA) have been investigated by spectral-luminescent methods. Fluorescence quenching of tryptophan residues caused by the inductive-resonance energy transfer to pigment molecules and the rise of the polarization degree of Chl e6 emission were observed upon incorporation of Chl e6 in the protein globula. The obtained data on spectral-energetic parameters of protein tryptophanyls and Chl e6 permitted us to calculate the energy transfer critical distances R0 in complexes of Chl e6 with HSA (R0 = 32 A) and BSA (R0 = 35A). The binding constants (K) and the number of binding sites (N) of Chl e6 with HSA and BSA have been obtained from the experiments on tryptophanyl fluorescence quenching of the investigated proteins and polarization measurements of pigment emission (KHSA = 1.2.10(6) mole-1, KBSA = 3.6.10(6) mole-1, NHSA = NBSA = 1). On the basis of the measured values of electronic excitation energy transfer efficiency (phi greater than or equal to 99%) the average distances between the protein chromophores and the incorporated Chl e6 molecules have been calculated (RHSA = 15-17 A, RBSA = 16.5-18 A). The questions connected with pigment localization sites in the protein globula and specific features of pigment-protein interaction are discussed.
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PMID:[Characteristics of complex-formation of chlorine e6 with human and bovine serum albumins]. 318 37

The metabolic fate of 14C-netilmicin (14C-NTL) was studied in rats after intramuscular administration (20 mg/kg). 1. Binding ratio of 14C-NTL to rat plasma protein, determined by the ultracentrifugal method, was 15 approximately 20% during the first 1 hour after intramuscular administration. 2. Binding ratio of 14C-NTL to HSA, determined by the equilibrium dialysis method, was 15 approximately 23%. Binding constant (K) and maximum binding number (n) were calculated as 1.48 X 10(4) and 3.3 mole/mole, respectively. Half of 14C-NTL bound to HSA was dissociated from HSA by gel-filtration. 3. The radioactivity in tail vein blood reached peak level at 10 minutes after intramuscular administration and declined rapidly. 4. Since the distribution rate of 14C-NTL into the blood cells was low during the first 2 hours, the plasma level at that time was about 1.5 times higher than whole blood level. 5. The recovery of radioactivity in the bile (0 approximately 24 hours) was only 0.13% of the dose administered. An average concentration during 2 hours after intramuscular injection was 2.5 mcg/ml. 6. Within 2 hours after administration, approximately 40% of the dose was recovered in the urine. Within 24 hours, 87.8% of the dose was excreted in the urine, 2.6% in the feces, 0.3% in the cage washing and 8.8% in the carcass. Total recovery ratio was 99.5% of the dose. 7. The radioactivity was widely distributed in the tissues, especially high in the kidney and bone, low in the brain. A high concentration of radioactivity was found in the renal cortex at 24 hours after administration. 8. Netilmicin was excreted into the urine unchanged and no metabolites were detected by TLC at all.
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PMID:[Absorption, distribution, metabolism and excretion of netilmicin in rats (III). Metabolic fate of 14C-netilmicin after intramuscular administration (author's transl)]. 709 91

A simple, sensitive and direct spectrophotometric method is presented for the determination of epsilon-amino groups of L-lysine present in carrier proteins, using the free amino acids L-lysine and L-glutamic acid as reference standards, and 2,4,6-trinitrobenzene 1-sulfonic acid (TNBS) reagent. The amount of epsilon-amino group present in the carrier protein after coupling with hapten is directly quantitated using the standard curve generated by the difference in absorbance observed with L-lysine and L-glutamic acid after their reaction with TNBS reagent. Spectral analysis of L-lysine and L-glutamic acid (27.36 nmol) derivatives of TNBS at 335 nm showed that TNP-L-lysine had twice the absorbance of TNP-L-glutamic acid, since TNBS reagent interacts equally with the alpha-amino and epsilon-amino groups present in L-lysine and the alpha-amino group of L-glutamic acid, respectively. The relationship between absorbance and concentration of epsilon-amino groups (up to 16 micrograms/ml) was found to be linear. The number of epsilon-amino groups of lysine present in carrier proteins such as BSA, HSA, thyroglobulin and the enzyme, horseradish peroxidase, were analyzed by the present method and were found to be similar to the reported values. Various carrier protein-hapten conjugates (protein-mycotoxin/vitamin/steroid hormone conjugates) were made and analyzed by the method developed in order to determine their mole to mole ratio.
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PMID:Quantitation of epsilon-amino group using amino acids as reference standards by trinitrobenzene sulfonic acid. A simple spectrophotometric method for the estimation of hapten to carrier protein ratio. 790 97

Cosalane is a potent inhibitor of HIV replication with multiple sites of action. The purposes of this study were to (a) determine the extent and nature of cosalane binding to mucin, alpha(1)-acid glycoprotein (AAG), plasma, and human (HSA) and bovine serum (BSA) albumin, and (b) determine the primary site(s) of cosalane binding to HSA. Plasma protein binding of cosalane was studied by a gel filtration technique. Cosalane binding to HSA was also determined in the presence of salicylic acid. Competitive inhibition studies were conducted using warfarin, digitoxin, and diazepam to determine the primary HSA binding site(s) of cosalane. The drug was bound extensively to HSA and BSA and required 500-550 moles to saturate 1 mole of protein. Stoichiometries of cosalane binding to alpha(1)-acid glycoprotein (AAG) and mucin were between 30 and 50 mol/mol of either glycoprotein. The binding isotherm deviated from a rectangular hyperbola, suggesting self-association of the ligand. Salicylic acid decreased cosalane binding to HSA by one order of magnitude. Inhibition studies of cosalane to HSA revealed that the compound binds primarily to warfarin site with a K(i) of 1.24 +/- 0.24 nM. In summary, cosalane binds extensively to serum albumins and to a lesser extent to both AAG and mucin.
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PMID:Binding of cosalane--a novel highly lipophilic anti-HIV agent--to albumin and glycoprotein. 1128 10

The objective of this study was to develop a liver-specific antihepatocarcinoma agent. The galactosylated human serum albumin 5-fluorouracil conjugate (GHSA-5-FU) was prepared and tested for its chemical characteristic, biodistribution and primary cytotoxicity. The matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was applied to determined the molar ratio (moles of 5-FU/mole of G-HSA and moles of galactose/mole of HSA) of the conjugate. The liver targeting ability of GHSA-5-FU labeled by (131)I was evaluated by measuring the total radioactivity in organs after i.v. administration in mice and rabbits, and the cytotoxicity of the conjugate was assayed by MTT method. The results showed that the molar ratio of galactose to HSA was 50, and the 5-FU to GHSA was 15. Liver uptake in rabbits and mice peaked within 5-20 min after injection. The radioactivity (counts/g tissue) of the conjugate in the liver was several times higher than those in the other organs. The conjugate showed strong cytotoxicity, but no significant cytotoxicity difference was found between GHSA-5-FU and free 5-FU.
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PMID:Enhanced liver targeting of 5-fluorouracil using galactosylated human serum albumin as a carrier molecule. 1660 32

A Vroman-like exchange of different proteins adsorbing from a concentrated mixture to the same hydrophobic adsorbent surface is shown to arise naturally from the selective pressure imposed by a fixed interfacial-concentration capacity (w/v, mg/mL) for which protein molecules compete. A size (molecular weight, MW) discrimination results because fewer large proteins are required to accumulate an interfacial w/v concentration equal to smaller proteins. Hence, the surface region becomes dominated by smaller proteins on a number-or-mole basis through a purely physical process that is essentially unrelated to protein biochemistry. Under certain conditions, this size discrimination can be amplified by the natural variation in protein-adsorption avidity (quantified by partition coefficients P) because smaller proteins (MW<50 kDa) have been found to exhibit characteristically higher P than larger proteins (MW<50 kDa). The standard depletion method is implemented to measure protein-adsorption competition between two different test proteins (i and j) for the same hydrophobic octyl sepharose adsorbent particles. SDS-gel electrophoresis is used as a multiplexing, separation-and-quantification tool for this purpose. Identical results obtained using sequential and simultaneous competition of human immunoglobulin G (IgG, protein j) with human serum albumin (HSA, protein i) demonstrates that HSA was not irreversibly adsorbed to octyl sepharose over a broad range of competing solution concentrations. A clearly observed exchange of HSA for IgG or fibrinogen (Fib) shows that adsorption of different proteins (i competing with j) to the same hydrophobic surface is coupled whereas adsorption among identical proteins (i or j adsorbing from purified solution) is not coupled. Interpretive theory shows that this adsorption coupling is due to competition for the fixed surface capacity. Theory is extended to hypothetical ternary mixtures using a computational experiment that illustrates the profound impact size-discrimination has on adsorption from complex mixtures such as blood.
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PMID:Volumetric interpretation of protein adsorption: competition from mixtures and the Vroman effect. 1700 20

The interactions of the new photosensitizer {2, 3, 9, 10, 16, 17, 23, 24-octakis[(3,5-dicarboxy)phenoxy]-phthalocyaninato}zinc(II) [ZnPc(COOH)16] and serum albumins (BSA and HSA) were investigated by absorption and fluorescence spectroscopy. The binding constants were found to be 2.25-2.94 x 10(6) L x mol(-1). The 1 : 1 ZnPc (COOH)16-BSA and ZnPc (COOH)16-BSA conjugates were also prepared by incubating a mixture of ZnPc(COOH)16 and the corresponding serum albumin in 2 : 1 mole ratio followed by separation by gel permeation chromatography. The Q band absorption and fluorescence emission of ZnPc(COOH)16 are slightly red-shifted in the conjugates, and the spectral features suggest that the phthalocyanine exists predominantly in monomeric form in the conjugates.
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PMID:[Spectroscopic studies on the interactions of a hexadeca-carboxy zinc phthalocyanine and serum albumin and preparation of the bioconjugates]. 1705 28


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