human serum albumin (hsa) is the most abundant protein in the blood plasma. drug binding to hsa is crucial to study the absorption, distribution, metabolism, efficiency and bioavailability of drug molecules. in this study, isothermal titration calorimetry and molecular dynamics simulation of hsa and its complex with indometacin (im) were performed to investigate thermodynamics parameters and th...

the purification of biomolecules is a necessary step in many biochemical researches. in this regard, developments of convenient, specific and low cost methods of purification are of particular interest. given the human hemoglobin (hb) affinity toward some charged carbohydrates, interaction of this molecule with human chorionic gonadotropin (hcg) which is a glycoprotein hormone containing sialic...

A model in which two positively-charged titratable sites enhance the affinity for anionic substrates can explain the increase in external iodide dissociation constant (K(O)(I)) with increasing pH(O) (Liu, S. J., F.-Y. Law, and P.A. Knauf. 1996.f Gen.Physiol. 107:271-291). If sulfate binds to the same external site as I-, this model predicts that the SO(4)= dissociation constant (K(O)(S)) should...

We have selected aptamers binding to lysozyme from a DNA library using capillary electrophoresis-systematic evolution of ligands by exponential enrichment. During the selection process the dissociation constant of the ssDNA pool decreased from the micromolar to the low nanomolar range within five rounds of selection. The final aptamer had a dissociation constant of 2.8 +/- 0.3 nM, 6.1 +/- 0.5 n...

The mutL gene of Escherichia coli, which is involved in the repair of mispaired and unpaired nucleotides in DNA, has been independently cloned and the gene product purified. In addition to restoring methyl-directed DNA repair in extracts prepared from mutL strains, the purified MutL protein binds to both double and single stranded DNA. The affinity constant of MutL for unmethylated single stran...

Almtract--1. Properties of hemoglobins in the blood of the salamanders Cryptobranchus alleganiensis, Necturus maculosus and Hynobius tsuensis were examined by starch gel electrophoresis and peptide mapping. 2. Multiple hemoglobin components were found in individual specimens of N. maculosus and H. tsuensis, but a single component was observed in C. alleganiemis. 3. Sedimentation coefficients of...

A sex steroid-binding protein (SBP) that binds to 17 b-estradiol with high affinity and moderate capacity was identified in the plasma of female and juvenile of kutum (Rutilus frisii kutum) sampled during the early stage of gonadal maturation in October and prior to spawning in March. Mean maximum specific binding (Bmax) and equilibrium dissociation constant (Kd) of the fish were as follows: In...

Background: Artificial oligonucleotides like DNA or RNA aptamers can be used as biodiagnostic alternatives for antibodies to detect pathogens. Comparing to antibodies, artificial oligonucleotides are produced easily at lower costs and are more stable. Neisseria meningitidis, the causative agent of meningitis, is responsible for about 1% of infections in an epidemic period. Specific DNA aptamers...

A simplified method has been developed for the determination of antibody-hapten association kinetics that permits the study of high affinity interactions with second order forward rate constants of the order of 10-7 to 10-8 M-1 sec-1. Use of tritiated haptens of high specific activity and antibodies of high affinity allows reactions to be run at initial hapten and antibody concentrations of the...

The interactions of dipyridamole with alpha(1) acid glycoprotein of plasma and with human platelets are related to inhibition of adenosine uptake by platelets. Binding studies by equilibrium gel filtration suggested that 1 mol of dipyridamole binds per mol of alpha(1) acid glycoprotein with a dissociation constant of 1.6 muM. Platelets contain two populations of binding sites, one with high and...