Peroxin 11 (Pex11) is a peroxisome membrane protein of the yeast Saccharomyces cerevisiae. It has recently been assumed that Pex11 forms pores that allow the passage of solutes smaller than 400 Da. The aim of the thesis was to upgrade the mentioned study, by (i) obtaining recombinant Pex11 and verifying its pore-forming activity on unilamellar vesicles loaded with calcein, and (ii) checking the specificity of the pore for the transport of NADH and coenzyme A using the system of planar membranes. To obtain Pex11, two different strains and vectors were tested and evaluated for the yield of recombinant Pex11 under different cultivation conditions. The optimized cultivation process was transferred to a larger scale and we successfully isolated recombinant Pex11. In order to determine the lipid binding partner, we performed a sedimentation test and a lipid dot blot assay. The pore-forming activity was tested fluorimetrically on calcein-loaded unilamellar lipid vesicles composed of a total lipid extract of bovine erythrocytes or phosphatidylcholine. Although we were not able to determine the lipid receptor and pore specificity, vesicles from the total lipid extract of bovine erythrocytes confirmed, that Pex11 was a pore-forming protein.