Novel immunoglobulin-binding proteins and their use in affinity purification

摘要

The present disclosure relates to a non-natural binding protein comprising one or more non-natural immunoglobulin (Ig) binding domains, wherein at least one non-natural Ig-binding domain comprises an amino acid sequence X1X2X3XiXsX5X7 XsQQX11XYX1sX15LX1 sX19PX21 LX23X28X2X2XXXXXXXXXXX do. The present disclosure also relates to compositions, such as affinity matrices, comprising the non-natural Ig-binding proteins of the invention. Use of such Ig-binding proteins or compositions for affinity purification of immunoglobulins and methods of affinity purification.