Defining the repeating elements in the cysteine-rich region (CRR) of the CD18 integrin beta 2 subunit

The cysteine-rich region (CRR) of the integrin beta subunits is organised i nto four repeating elements. By expression of a panel of truncated beta2 su bunits, and CRR segments fused to the C-terminal end of a CD4 soluble fragm ent, the segment required for the expression of two monoclonal antibody con formational epitopes was determined. This segment, E482-Q574, contains 16 c ysteines representing two repeating units. We have thus defined the CRR uni t motif of 'xC-C-C-CxCxxCxC-Cx', where 'x' represents a single residue, and represents a stretch of four to 14 residues. (C) 2001 Published by Elsevie r Science B.V. on behalf of the Federation of European Biochemical Societie s.