We have studied the binding of alpha-bungarotoxin to a particulate fraction of goldfish brain enriched in synaptosomes. The binding is specific and saturable and exhibits the pharmacological properties of a nicotinic cholinergic receptor. Equilibrium binding measurements yield a single dissociation constant (KD) of 0.92 nM. Kinetic analysis revealed one association rate constant and two dissoci...

The j3 nerve growth factor (NGF) isolated from the high molecular weight 7 S NGF complex from mouse submaxillary gland is a protein of molecular weight 26,500 which contains two noncovalently associated peptide chains. A variety of techniques were employed to determine whether the NGF dimer dissociates at the low concentrations at which it is biologically active. No dissociation was detected in...

The dimer dissociation constant Kd is defined as the ratio of the concentrations of the monomers ( p1 ) and dimers ( p2 ) in steady state, i.e., Kd = p1 2 p2 . In terms of the basic kinetic parameters (the association rate ka and the dissociation rate kd ), the in vitro dissociation constant is simply Kd (0) = kd ka . However, the effective value of Kd is modified in vivo due to a variety of pr...

According to the classical theory of the dissociation of weak electrolytes, the amino acids show much lower basic and acidic dissociation constants than would be expected from a comparison with other weak acids and bases. In order to explain this anomaly, Adams (1) originally suggested that an ampholyte must necessarily exist almost entirely as an “inner salt.” Bjerrum (2) extended this idea wi...

Tris(vancomycin carboxamide) binds a trivalent ligand derived from D-Ala-D-Ala with very high affinity: dissociation constant (Kd) approximately 4 x 10(-17) +/- 1 x 10(-17) M. High-affinity trivalent binding and monovalent binding are fundamentally different. In trivalent (and more generally, polyvalent) binding, dissociation occurs in stages, and its rate can be accelerated by monovalent ligan...

Bovine brain GoK was specifically palmitoylated in vitro. The apparent dissociation constant for depalmitoylated GoK (dGoK) was 0.273 WM, while that for palmitoylated GoK (pGoK) was 5.77 nM. The dissociation rate constant (K21) and dissociation half-life for dGoK were 8.4U1034 min and 825 min respectively, while no significant dissociation of pGoK was detected. The limiting membrane insertion p...

The dissociation kinetics of cooperatively bound bacteriophage T4 gene 32 protein from a variety of single-stranded homopolynucleotides has been investigated by stopped-flow techniques. Irreversible dissociation of the complexes was induced by rapidly increasing the salt concentration and monitoring the increase in tryptophan fluorescence upon dissociation of the gene 32 protein. The dependence...