Purified polypeptide is proposed, the amino acid sequence of which is essentially identical to the amino acid sequence of SEQ ID NO:1 and SEQ ID NO:3, the polypeptide binding low density lipoproteins (LDL) and/or oxidized LDL (oxLDL), in particular LDL cholesterol and/or oxidized LDL cholesterol (oxLDL cholesterol).The invention includes the use of the polypeptide in combination with conventional adjuvants and/or carrier substances for producing a drug having a fat-reducing effect and for producing drugs for treating renal diseases.