Abstract: Peptides characterized by: a) a sequence selected from the group consisting of the sequence SEQ ID NO: 2, and the derived variants having at least 70% identity or 80% similarity with the entire sequence SEQ ID NO: 2, b) a three-finger structure including eight cysteine residues linked by four disulfide bridges, respectively between the first and the third cysteine, the second and the fourth cysteine, the fifth and the sixth cysteine, and the seventh and the eighth cysteine, and c) an activity of an allosteric antagonist selective for the alpha 1a adrenergic receptor, and therapeutic and pharmacological uses thereof.

Abstract: The present invention relates to a method for preparing an antibody selective for activating antibody Fc region receptors (FcRs) comprising an ITAM motif or motifs (immunoreceptor tyrosine-based activation motif), comprising the steps of obtaining monoclonal antibodies from a hybridoma, from a heterohybridoma or from any animal, plant or human cell line, replacing each of the His 310 and His 435 residues (Cabat numbering) of the Fc region of said antibody with a residue chosen from lysine, alanine, glycine, valine, leucine, isoleucine, proline, methionine, tryptophan, phenylalanine, serine or threonine, and then selecting the antibodies for which the binding to inhibitory FcRs comprising ITIM motifs (immunoreceptor tyrosine-based inhibition motif) is decreased by at least 30%, preferably by at least 50%, 70%, 80% or else by at least 90% relative to the same antibody having a natural Fc region.