C-Terminal Region of Caveolin-3 Contains a Stretch of Amino Acid Residues Capable of Diminishing Symptoms of Experimental Autoimmune Encephalomyelitis but Not Rheumatoid Arthritis Modeled in Rats.

A short synthetic peptide from the C-terminal part of the caveolin-3 structure was tested for experimental autoimmune encephalomyelitis (EAE) treatment in rats. The structure-function similarity established between the novel synthetic peptide of pCav3 and the well-known immunomodulator immunocortin determined pCav3's ability to reduce EAE symptoms in Dark Agouti (DA) rats injected with pCav3 (500 µg/kg). pCav3 was found to interfere with the proliferation of lymphocytes extracted from the LNs of DA rats primed with homogenate injection, with IC = 0.

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 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.

Interaction of synthetic peptide octarphin (TPLVTLFK) with human blood lymphocytes.

The synthetic peptide octarphin (TPLVTLFK) corresponding to the sequence 12-19 of β-endorphin, a selective agonist of non-opioid β-endorphin receptor, was labeled with tritium to specific activity of 29 Ci/mmol. The analysis of [(3) H]octarphin binding to human T and B lymphocytes separated from normal human blood revealed the existence of one type of high-affinity binding sites (receptors): Kd 3.0 and 3.

Synthetic peptide octarphin (TPLVTLFK) inhibits the activity of the hypothalamus-pituitary-adrenal axis through nonopioid β-endorphin receptor.

The synthetic peptide octarphin (TPLVTLFK) corresponding to the sequence 12-19 of β-endorphin, a selective agonist of nonopioid β-endorphin receptor, was labeled with tritium to specific activity of 29 Ci/mmol. The analysis of [(3)H]octarphin binding to rat pituitary and adrenal cortex membranes revealed the existence of one type of binding sites (receptors): Kd 5.9 and 35.

Synthetic peptide TPLVTLFK (octarphin) reduces the corticosterone production by rat adrenal cortex through nonopioid β-endorphin receptor.

The synthetic peptide octarphin (TPLVTLFK) corresponding to the sequence 12-19 of β-endorphin, a selective agonist of nonopioid β-endorphin receptor, was labeled with tritium to a specific activity of 29 Ci/mmol. [(3)H]Octarphin was found to bind to high-affinity naloxone-insensitive binding sites on membranes isolated from rat adrenal cortex (K(d) = 35.7 ± 2.

Detection of nonopioid β-endorphin receptor in the rat myocardium.

Two selective agonists of nonopioid β-endorphin receptor, synthetic peptides TPLVTLFK (octarphin) and SLTCLVKGFY (immunorphin), were labeled with tritium to specific activity of 29 and 25 Ci/mmol, respectively. Both labeled peptides were found to bind to high-affinity naloxone-insensitive binding sites on the membranes isolated from the rat myocardium (Kd = 2.0 ± 0.

Binding of synthetic peptide TPLVTLFK to nonopioid beta-endorphin receptor on rat brain membranes.

The synthetic peptide TPLVTLFK corresponding to the sequence 12-19 of beta-endorphin (referred to as octarphin) was found to bind to high-affinity naloxone-insensitive binding sites on membranes isolated from the rat brain cortex (K(d) = 2.6 +/- 0.2 nM).

Binding of synthetic fragments of beta-endorphin to nonopioid beta-endorphin receptor.

Selective agonist of nonopioid beta-endorphin receptor decapeptide immunorphin (SLTCLVKGFY) was labeled with tritium (the specific activity of 24 Ci/mmol). [3H]Immunorphin was found to bind to nonopioid beta-endorphin receptor of mouse peritoneal macrophages (Kd = 2.0 +/- 0.

Interaction of ACTH synthetic fragments with rat adrenal cortex membranes.

Synthetic peptide, corresponding to the amino acid sequence 11-24 of human adrenocorticotropic hormone (ACTH), was labeled with tritium (specific activity of 22 Ci/mmol). [(3)H]ACTH (11-24) was found to bind to rat adrenal cortex membranes with high affinity and specificity (K(d) = 1.8 +/- 0.

Beta-endorphin-like peptide SLTCLVKGFY reduces the production of 11-oxycorticosteroids by rat adrenal cortex through nonopioid beta-endorphin receptors.

Beta-endorphin-like peptide immunorphin (SLTCLVKGFY), a selective agonist of nonopioid beta-endorphin receptor, was labeled with tritium to specific activity of 24 Ci/mmol. It was used for the detection and characterization of nonopioid beta-endorphin receptors on rat adrenal cortex membranes (Kd = 31.6 +/- 0.

The Stimulating Effect of the beta-Endorphin-Like Peptide Immunorphin on the Human T-Lymphoblastoid Cell Line Jurkat Is Mediated by a Non-Opioid Receptor for beta-Endorphin.

It was shown that beta-endorphin and the synthetic decapeptide SLTCLVKGFY that corresponds to the amino acid sequence 364-373 of the human IgG heavy chain (referred to as immunorphin) is able to stimulate growth of the human T-lymphoblastoid cell line Jurkat. The antagonist of opioid receptors naloxone did not inhibit the stimulating effect of the peptides. Studies on [(3)H]-immunorphin binding to Jurkat cell receptors have demonstrated that it binds with high affinity to naloxone-insensitive receptors (K(d) = 1.

Effect of beta-endorphin and beta-endorphin-like peptide immunorphin on the growth of human leukemic cells in vitro.

The influence of beta-endorphin and immunorphin on human leukemic cell growth in vitro was studied. It was shown that both peptides increase the growth of T-lymphoblastoid cells in a dose-dependent manner. The effect of these peptides on the 3H-thymidine incorporation into T-lymphoblastoid cell line Jurkat was not reversed by the antagonist of opioid receptor naloxone.

Synthetic peptide SLTCLVKGFY competes with beta-endorphin for naloxone-insensitive binding sites on rat brain membranes.

The synthetic decapeptide Ser-Leu-Thr-Cys-Leu-Val-Lys-Gly-Phe-Tyr (termed immunorphin) corresponding to the sequence 364-373 of the CH3 domain of human immunoglobulin G heavy chain and its synthetic fragment VKGFY were found to compete with 125I-labeled beta-endorphin for high-affinity naloxone-insensitive binding sites on membranes isolated from the rat brain cortex (K(i)=1.18+/-0.09 and 1.