Rabbits transgenic for human IgG genes recapitulating rabbit B-cell biology to generate human antibodies of high specificity and affinity.

Transgenic animals incorporating human antibody genes are extremely attractive for drug development because they obviate subsequent antibody humanization procedures required for therapeutic translation. Transgenic platforms have previously been established using mice, but also more recently rats, chickens, and cows and are now in abundant use for drug development. However, rabbit-based antibody generation, with a strong track record for specificity and affinity, is able to include gene conversion mediated sequence diversification, thereby enhancing binder maturation and improving the variance/selection of output antibodies in a different way than in rodents.

Efficient immunoglobulin gene disruption and targeted replacement in rabbit using zinc finger nucleases.

Rabbits are widely used in biomedical research, yet techniques for their precise genetic modification are lacking. We demonstrate that zinc finger nucleases (ZFNs) introduced into fertilized oocytes can inactivate a chosen gene by mutagenesis and also mediate precise homologous recombination with a DNA gene-targeting vector to achieve the first gene knockout and targeted sequence replacement in rabbits. Two ZFN pairs were designed that target the rabbit immunoglobulin M (IgM) locus within exons 1 and 2.

A superrepressor mutant of the arginine repressor with a correctly predicted alteration of ligand binding specificity.

Arginine biosynthesis in Escherichia coli is negatively regulated by the hexameric repressor protein ArgR and the corepressor L-arginine. L-Arginine binds to ArgR in the C-terminal domain of the repressor. Binding to operator DNA occurs in the N-terminal domain.

Synthesis and secretion of recombinant penicillin G acylase in bacterial L-forms.

L-form strains of Proteus mirabilis and Escherichia coli lacking the cell wall represent an alternative prokaryotic cell system for the production of recombinant proteins (KLESSEN et al. 1988, LAPLACE et al. 1988a, 1989b).

The DNA-binding domain of the hexameric arginine repressor.

The arginine repressor of Escherichia coli is a classical feedback regulator, signalling the availability of L-arginine inside the cell. It differs from most other bacterial repressors in functioning as a hexamer, but structural details have been lacking and its shares no clear sequence homologies with other transcriptional regulators. Analysis of the amino acid residue sequence and proteolytic cleavage pattern of the repressor was used to identify a region predicted to house the DNA-binding function.