The aim of this work was the exploitation of the C-terminal oligomerization domain of human C4BP (complement component C4b-binding protein) for applications as scaffold and adjuvant in the field of molecular biochemistry. Furthermore an expression system in the yeast Yarrowia lipolytica was evaluated for its potential as production system for C4BP based homo- and hetero oligomers. The evaluation was realized by recombinant production of three different model proteins. Within this study it was possible to solve the crystal structure of the C-terminal oligomerization domain of the 7α-isoform of human C4BP. This was achieved using isomorphic replacement exploiting the anomalous signal of selenium (PDB-ID: 4B0F). The heptameric structure has a torus-like shape in top view and a champagne cork-like shape in side view. In addition to the intermolecular disulfide bridges the oligomerization domain is stabilized by three layers of intermolecular interactions. CD-spectroscopy and Thermofluor measurements of different variants resulted in the accumulation of data about stability and tolerance of the oligomerization domain in respect to mutations as well as amino acid exchanges. The crystal structure of the 7α-isoform served as starting point for the generation of in silico models of the three other naturally occurring C4BP-isoforms (7α1β, 6α1β, 6α). In this context, the proposed positioning of the β-chain in the hetero oligomers appears to be rational. However, crucial questions concerning the assembling process e.g. the involvement of chaperons or in vivo regulation of subunit composition remain unclear. An in vitro polymerization of heterologous produced subunits was not achieved. However, these experiments yielded insights into the remarkable refolding capability of the oligomerization domain which might be useful in further experiments towards discrimination and separation of functionalized monomers. By successive truncation from the C- as well as the N-terminus of the C4BP α oligomerization domain it was possible to identify the part crucial for assembly and subunit polymerization. This minimal sequence comprises of 37 amino acids instead of 66 present in the wild type protein. Polymerization is initiated at the C-terminal helices H2 of the oligomerization domain. The N-terminal helices H1 do not seem to be involved in subunit polymerization. These insights in combination with the crystal structure enable for the exchange of some or all amino acids from L- to D-configuration, possibly further increasing overall stability and in vivo half-life. The expression system in the unconventional yeast Yarrowia lipolytica was evaluated as potential production system for C4BP-based homo and hetero oligomers. Using this system, it was possible to produce three model proteins (MCoTI, Tryp-VHH, Goase M1). These proteins, very different in there phylogenetic background, as well as size and complexity were secreted as Lip2p-fusion proteins resulting in reasonable yields and purity. Furthermore, the functionality of each protein was confirmed by individual activity assays (inhibition assay, binding assay and ABTS assay). However, the yield of protein of interest might be further increased by optimization of codon usage, fermentation conditions as well as the purification strategy. Finally, the capability of the Yarrowia lipolytica expression system should be tested for the production of functionalized C4BP oligomers. Possibly enabling for the recombinant production of fusion proteins, which were inaccessible by E. coli expression systems.