US Patent 11014967 Alkaline stable Fc-binding proteins for affinity chromatography

The present invention relates to Fc binding proteins comprising one or more Fc binding domains wherein at least one domain comprises of an amino acid sequence selected from the group consisting of SEQ ID NOs: 1-6 or 21. The invention further relates to affinity matrices comprising the Fc binding proteins of the invention. The invention also relates to a use of these Fc binding proteins or affinity matrices for affinity purification of immunoglobulins and to methods of affinity purification using the Fc binding proteins of the invention.