Binding of cholera toxin B subunit to intestinal epithelial cells.

We have prepared I-labeled cholera toxin B subunit (I-labeled CT-B, a specific activity of 98Ci/mmol) and found that it binds to rat IEC-6 and human Caco-2 intestinal epithelial cells with high affinity (K 3.6 and 3.7nM, respectively).

Interaction of Cholera Toxin B-subunit with Human T-lymphocytes.

In this work, I-labeled cholera toxin B-subunit (CT-B) (specific activity 98 Ci/mmol) was prepared, and its high-affinity binding to human blood T-lymphocytes (K = 3.3 nM) was determined. The binding of the I-labeled CT-B was inhibited by unlabeled interferon-α (IFN-α), thymosin-α (TM-α), and by the synthetic peptide LKEKK, which corresponds to sequences 16-20 of human TM-α and 131-135 of IFN-α (K 0.

Interaction of cholera toxin B subunit with T and B lymphocytes.

We have prepared I-labeled cholera toxin B subunit (I-labeled CT-B, a specific activity of 98Ci/mmol) and found that its binding to T and B lymphocytes from the blood of healthy donors was high-affinity (K 2.8 and 3.0nM, respectively).

Synthetic peptide octarphin (TPLVTLFK), a selective agonist of nonopioid β-endorphin receptor, stimulates nitric oxide synthesis in macrophages.

Synthetic peptide octarphin (TPLVTLFK, a selective agonist of nonopioid β-endorphin receptor) was able to activate in a dose-dependent manner murine macrophages to express nitric oxide (NO) synthase and to produce NO. Octarphin required lipopolysacharide for the optimal induction of NO production. Octarphin-dependent NO production was sensitive to inhibition by dexamethasone and the NO synthase specific inhibitor NG-monomethyl-L-arginine.

The ATP permeability of pannexin 1 channels in a heterologous system and in mammalian taste cells is dispensable.

Afferent output in type II taste cells is mediated by ATP liberated through ion channels. It is widely accepted that pannexin 1 (Panx1) channels are responsible for ATP release in diverse cell types, including taste cells. While biophysical evidence implicates slow deactivation of ion channels following ATP release in taste cells, recombinant Panx1 activates and deactivates rapidly.