Novel immunoglobulin-binding proteins and their use in affinity purification

摘要

The present disclosure relates to non-natural binding proteins comprising one or more non-natural immunoglobulin (Ig) binding domains wherein at least one non-natural lg-binding domain comprises the amino acid sequence X1 X2X3XiXsX5X7 XsQQX11AFYX1sX15LX1 sX19PX21 LX23X24X2sQRX28X2gf IQSLKDDPSXio SXi2Xi3Xi4LXi5EAXigKLXs2Xs3Xs4QXs5PX. The idisclosure also relates to compositions such as affinity matrices comprising the non-natural Ig-binding proteins of the invention. Use of these Ig-binding proteins or of the compositions for affinity purification of immunoglobulins and to methods of affinity purification.