Potent antagonism of 5-HT(3) and 5-HT(6) receptors by olanzapine.

The interaction of the psychotropic agent olanzapine with serotonin 5-HT(3) and 5-HT(6) receptors was investigated. Olanzapine did not contract the isolated guinea pig ileum, but blocked contractions induced by the 5-HT(3) receptor agonist 2-methyl serotonin (2-CH(3) 5-HT) with a pK(B) value of 6.38+/-0.

Immunological characterization of cell-surface and soluble forms of membrane type 1 matrix metalloproteinase in human breast cancer cells and in fibroblasts.

Membrane type (MT) 1 matrix metalloproteinase (MMP) activates progelatinase A (pro-MMP-2), a type IV collagenase, on the cell surface of tumors; however, its function in breast cancer progression and metastasis is not fully understood. To examine the expression of MT1-MMP in breast cancer cells and fibroblasts, a specific rabbit antibody (Ab) directed against a unique synthetic peptide derived from the human MT1-MMP catalytic domain was produced, purified, and characterized. This Ab is not likely to cross-react with MT2-, MT3-, or MT4-MMP or any other MMPs.

Identification and characterization of a novel collagenase in Xenopus laevis: possible roles during frog development.

Matrix metalloproteinases (MMPs) participate in extracellular matrix remodeling and degradation and have been implicated in playing important roles during organ development and pathological processes. Although it has been hypothesized for > 30 years that collagenase activities are responsible for collagen degradation during tadpole tail resorption, none of the previously cloned amphibian MMPs have been biochemically demonstrated to be collagenases. Here, we report a novel matrix metalloproteinase gene from metamorphosing Xenopus laevis tadpoles.

Cytoplasmic location of amino acids 359-440 of the Neurospora crassa plasma membrane H(+)-ATPase.

The topographic location of the region comprising amino acids 359-440 of the Neurospora crassa plasma membrane H(+)-ATPase has been elucidated using reconstituted proteoliposomes and protein chemical techniques. Proteoliposomes containing H(+)-ATPase molecules oriented predominantly with their cytoplasmic surface facing outward were cleaved with trypsin and the resulting digest was subjected to centrifugation on a glycerol step gradient to separate the released and liposome-bound peptides. The released peptides were recovered in the upper regions of the step gradient, whereas the liposome-bound peptides were recovered near the 40% glycerol interface.

Biochemical characterization of the cystic fibrosis transmembrane conductance regulator in normal and cystic fibrosis epithelial cells.

Affinity-purified polyclonal antibodies, raised against two synthetic peptides corresponding to the R domain and the C terminus of the human cystic fibrosis transmembrane conductance regulator (CFTR), were used to characterize and localize the protein in human epithelial cells. Employing an immunoblotting technique that ensures efficient detection of large hydrophobic proteins, both antibodies recognized and approximately 180-kDa protein in cell lysates and isolated membranes of airway epithelial cells from normal and cystic fibrosis (CF) patients and of T84 colon carcinoma cells. Reactivity with the anti-C terminus antibody, but not with the anti-R domain antibody, was eliminated by limited carboxypeptidase Y digestion.