Antibacterial properties of hemerythrin of the sand worm Nereis diversicolor.

Objectives: To investigate the immune defense of the annelid Nereis diversicolor and the key role of a oxygen-binding protein, the metalloprotein MPII animals were subjected to bacteria infection.

Methods And Results: Using RACE-PCR, we have cloned the complete cDNA coding for the MPII related to the hemerythrin family in the sand worm Hediste diversicolor. This cDNA (883 pb) codes for a polypeptide of 119 amino acid residues with no signal peptide.

Morphine-like substance in leech ganglia. Evidence and immune modulation.

Binding experiments followed by measurement of nitric oxide release revealed an opiate alkaloid high affinity receptor with no affinity to opioids, representing a new mu-subtype receptor in the brain of the leech Theromyzon tessulatum. In addition, evidence of morphine-like substances was found in immunocytochemical studies and HPLC coupled to electrochemical detection (500 mV and 0.02 Hz).

Mu3 opiate receptor expression in lung and lung carcinoma: ligand binding and coupling to nitric oxide release.

The mu3 opiate receptor subtype is expressed in human surgical specimens of both normal lung and non-small-cell lung carcinoma. Nitric oxide (NO) release is mediated through the mu3 receptor, and in lung carcinoma, morphine-stimulated NO release is significantly higher and prolonged than in normal lung. Using reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis we show that specific mu opioid receptor transcripts are present in lung carcinoma and other cells with the mu3 profile.

Putative leech dopamine1-like receptor molecular characterization: sequence homologies between dopamine and serotonin leech CNS receptors explain pharmacological cross-reactivities.

The biochemical characterization of a serotonin (5HT) receptor and the cloning of a dopamine (DA) receptor in the central nervous system (CNS) of the leech, Theromyzon tessulatum, is presented. Additionally, DA and 5HT binding sites were examined in the CNS by Scatchard analysis which showed a single, relatively high-affinity binding site with a Kd 1.1 nM and a Bmax 126+18 fmol/mg protein for [3H]DA and a Kd 2.

Isolation and characterization of a leech neuropeptide in rat brains: coupling to nitric oxide release in leech, rat and human tissues.

The osmoregulator peptide (leech osmoregulatory factor, LORF; IPEPYVWD) was first found in the leech central nervous system (CNS). Given the fact that certain peptides can be found in mammals and invertebrates, e.g.