Generation of diversity in combinatorial libraries

Abstract

The invention concerns gene banks and combinatorial derivatives thereof, prepared using phagemid- or phage-display in combination with type IIS restriction enzymes and cosmid packaging; their use for the isolation of ligands, including enzyme inhibitors, agonists and antagonists for receptors, competitive binding peptides to a defined target, diagnostic ligands for diseases and autoimmune syndromes, including surveillance tools for immune status, post-translationally modified peptides, and such ligands generated by this technology.

1 . A bank of genes, wherein said genes comprise a double stranded DNA sequence which is represented by the following formula of one of their strands:  
         5′B 1 B 2 B 3  . . . B n X n+1  . . . X n+a Z n+a+1 X n+a+2 Z n+a+3  . . . X n+a+b Q n+a+b+1  . . . Q n+a+b+j 3′ wherein n, a, b and j are integers and      n>3, a>1, b>3 and j>1,   wherein X n+1  . . . X n+a+b  is a hypervariable sequence and B, X, Z and Q represent adenine (A), cytosine (C), guanine (G) or thymine (T),    (i) Z represents G or T at a G:T ratio of about 1:1, and/or    (ii) Z represents C or T at a C:T ratio of about 1:1, and/or    (iii) Z represents A or G at a A:G ratio of about 1:1, and/or    (iv) Z represents A or C at a A:C ratio of about 1:1, and wherein    subsequences B 1  . . . B n  and/or Q n+a+B+1  . . . Q n+a+b+j  represent recognition sites for restriction enzymes, and wherein the recognition sites are orientated such that their cleavage site upon cleavage generates a cohesive end including the two bases designated Z.    
     
     
         2 - 50 . (canceled)