Abstract: An isolated human anti-TNF-? antibody, or antigen-binding portion thereof, containing at least one high-affinity VL or VH antibody chain that is effective, when substituted for the corresponding VL or VH chain of the anti-TNF-? scFv antibody having sequence SEQ ID NO: 1, to bind to human TNF-? with a Koff rate constant that is at least 1.5 fold lower than that of the antibody having SEQ ID NO: 1, when determined under identical conditions.

Abstract: A method of walk-through mutagenesis of a nucleic acid encoding a prototype polypeptide of interest, is described, the method comprising selecting a predetermined amino acid and one or more target regions of the polypeptide, and synthesizing a mixture of oligonucleotides containing at each sequence position in the target region, either a prototype nucleotide that is required for synthesis of the prototype amino acid of the polypeptide, or a predetermined nucleotide that is required for synthesis of the predetermined amino acid, in which during the synthesis, the ratio of available prototype nucleotides, to available predetermined nucleotides, is greater than 1:1.