intact human platelets bind cytochalasin B (CB) with a capacity of 100-120 p mols CBimg protein or approximately 7 x lo4 rnoleculeslcell and dissociation constants (KD) ranging from 2 x 10" to lo6 M. Up to 85% of this saturable binding is displaced by 'lo+ M cytochalasin E (CE). This CE-sensitive bi
Binding of cytochalasin B to platelets
β Scribed by McDonald K. Horne III
- Publisher
- John Wiley and Sons
- Year
- 1989
- Tongue
- English
- Weight
- 562 KB
- Volume
- 39
- Category
- Article
- ISSN
- 0730-2312
No coin nor oath required. For personal study only.
β¦ Synopsis
The binding of cytochalasin B (CB) to human platelets and to isolated platelet cytosol and membranes has been analyzed with [3H]CB. High-and low affinity classes of saturable binding sites were associated with intact platelets. Binding at very low concentrations of CB (i.e., high-affinity binding) was partially prevented by 100 mM D-galatose or D-glucose and to a much lesser extent by L-glucose. Binding to platelet cytosol also involved two classes of sites with affinities and capacities similar to those observed with the whole cells. None of this binding, however, was affected by 100 mM D-galactose. Saturable binding to platelet membranes occurred at sites with a uniform binding affinity. Approximately 52 % of this binding was prevented by 1 M D-galactose and another 15% by cytochalasin E (CE). We hypothesize that binding in the cytosol is to monomeric (lowaffinity) and polymerized (high-affity) actin, whereas membrane binding (highaffinity only) occurs primarily at sites involved with galactose transport.
π SIMILAR VOLUMES
## Abstract Cytochalasin B (CB) was able to compete with tritiated cytochalasin D (^3H^βCD) for binding sites in HEpβ2 cells. The pattern of inhibition suggested that CB associates with a low affinity class of CD binding sites. Glucose and maltose did not inhibit binding of ^3^HβCD to isolated HEpβ
## Abstract The binding of tritiumβlabelled cytochalasin B (^3^HβCB) to a variety of mammalian cells was investigated. Binding studies revealed nearβequilibrium binding of ^3^HβCB within 5 to 10 minutes, but the equilibrium level was influenced by ^3^HβCB concentration. Binding kinetics revealed st
## Abstract To study the molecular basis of changes in sugar uptake rate in cultured mouse fibroblasts with different physiological states, we have measured the high affinity binding of [^3^H] cytochalasin B, a potent sugar transport inhibitor, to actively growing and contact inhibited Balb/3T3 cel