The invention relates to a multimeric molecule which can imitate a natural multimeric proteinaceous ligand. The invention also relates to a multimeric molecule as defined above which is characterised in that it has the following general formula: A-X.sub.n, wherein: n is equal to 3, 4, 5 or 6; A denotes a chemical group which is functionalised by at least three amine functions or COOH functions; and X denotes a D, B-D or B(D)-D' group, in which B is a spacer and D and D' are peptides or pseudopeptides corresponding to a sequence which is derived from the ligand and selected from residual matter forming the interface with the receptor and which can interact with the receptor.