Disclosed are concatameric proteins comprising two soluble domains, in which the C-terminus of a soluble domain of a biologically active protein is linked to the N-terminus of an identical soluble domain or a distinct soluble domain of a biologically active protein. Also, the present invention discloses dimeric proteins formed by formation of intermolecular disulfide bonds at the hinge region of two monomeric proteins formed by linkage of a concatamer of two identical soluble extracellular regions of proteins involving immune response to an Fc fragment of an immunoglobulin molecule, their glycosylated proteins, DNA constructs encoding the monomeric proteins, recombinant expression plasmids containing the DNA construct, host cells transformed or transfected with the recombinant expression plasmids, and a method of preparing the dimeric proteins by culturing the host cells. Further, the present invention discloses pharmaceutical or diagnostic compositions comprising the dimeric protein or its glycosylated form.