METHOD OF IDENTIFYING HETEROMULTIMERIC MODIFIED UBIQUITIN PROTEINS POSSESSING ABILITY TO BIND WITH LIGANDS Russian patent published in 2015 - IPC C07K14/00 C12N5/10 C12N7/00 C12N15/10 C12N15/62 C40B30/04 C40B40/06 C40B40/10 

FIELD: chemistry.

SUBSTANCE: invention relates to the field of biotechnology and can be used for the identification of heteromultimeric ubiquitins possessing an ability to bind with a ligand-antigen. The method includes the contact of a totality of heterodimeric modified ubiquitins, including two ubiquitin monomers, bound to each other by a head-to-tail scheme, with the potential ligand in a display way. Each of the said monomers is modified in a different way and contains 5-8 substitutions in positions 2, 4, 6, 8, 62, 63, 64, 65, 66 and 68 SEQ ID NO:1. After that, a heterodimeric modified protein, which has bound with the ligand with the binding affinity Kd in the range of 10^-7-10^-12 M and the monovalent binding activity. Claimed are DNA-libraries, responsible for obtaining a population of the said heteromultimeric ubiquitins, as well as libraries of proteins, obtained by the expression of the said DNA-libraries.

EFFECT: invention makes it possible to obtain the novel bonding proteins based on heteromultimeric ubiquitin, capable of specific high affinity binding with the selected ligands.

8 cl, 17 dwg, 4 ex