Abstract: Methods and composition for the preparation of gene libraries of antibodies or parts of antibodies which contain the variable domains. For example, in certain aspects methods for providing polynucleotide library involving annealing and extending are described. Furthermore, the invention provides polynucleotide or antibody fragment libraries prepared by the methods.

Abstract: Methods and compositions for the screening and isolation of ligand-binding polypeptides, such as antibodies. In some aspects, methods of the invention enable the isolation of intact soluble antibodies comprising a constant domain. Screening methods that employ genetic packages such as bacteria and bacteriophages enable high through-put identification of ligand binding molecules.

Abstract: The present invention relates to a polynucleotide construct encoding a fusion protein consisting of a domain which binds the immunoglobulin Fc region, genetically fused to a truncated form of Pseudomonas exotoxin A (PE). In particular, the invention discloses the fusion protein, ZZ-PE38, and further provides immunotoxins, formed from complexes of the fusion protein with antibodies for targeted cell killing.