Synthetic Human Peptide Research Articles

The N-Terminal Tandem Repeat Region of Human Prion Protein Reduces Copper: Role of Tryptophan Residues

Prion protein (PrP) has attracted considerable attention, mainly due to its involvement in transmissible spongiform encephalopathies. Toward its N-terminal region, PrP bears an octapeptide repeat which has been shown to bind copper. We found that a human synthetic peptide (PrP59–91), corresponding to the four repeats of Pro-His-Gly-Gly-Gly-Trp-Gly-Gln has the ability to reduce copper. A mutant peptide lacking tryptophan displayed only 24% of the wild-type copper-reducing activity. Experiments performed in a N2 environment confirmed that O2 is not involved in the reaction. Our results indicated that cell surface PrP, besides its ability to bind copper, bears the capacity to reduce copper in vitro. The potential physiological role of copper reduction by PrP is discussed.

P-glycoprotein epitope mapping. II. The murine monoclonal antibody MM6.15 to human multidrug-resistant cells binds with three distinct loops in the MDR1-P-glycoprotein extracellular domain.

A new murine monoclonal antibody (MAb), MM6.15, to human MDR1 P-glycoprotein was found to be reactive in ELISA with synthetic peptides selected from the predicted sequences of the first, fourth and sixth extracellular loop of MDR1-P-glycoprotein. In order to precisely define the MM6.15-binding site, a peptide library of overlapping 5- to 9-mer residues covering the entire sixth extracellular loop of both human and rodent class-1 P-glycoproteins was synthesized on polyethylene pins and tested for MAb binding. The results of this ELISA demonstrated that the MAb MM6.15 reacts only with human synthetic peptides and that the critical component of the MAb recognition is made up of the amino-acid sequence LVAHKL (residues 963-968 of the MDR1-P-glycoprotein) with histidine (H), lysine (K) and possibly leucine (L), key residues of this immunogenic domain.

Mechanism of elevation of glomerular filtration rate induced by synthetic human atrial natriuretic peptide in isolated perfused rat kidney.

Mechanism of elevation of glomerular filtration rate induced by synthetic human atrial natriuretic peptide in isolated perfused rat kidney.