Abstract: A process is provided for the production of an antibody or a fragment or functionalized fragment thereof using a transformed lower eukaryotic host containing an example DNA sequence encoding the antibody or (functionalized) fragment thereof, wherein the antibody or (functionalized) fragment thereof is derived from a heavy chain immunoglobulin of Camelidae and is devoid of light chains, and wherein the lower eukaryotic host is a mould, preferably belonging to the genera Aspergillus or Trichoderma, or a yeast, preferably belonging to the yeast genera Saccharomyces, Kluyveromyces, Hansenula, or Pichia. The heavy chain fragment can contain at least the whole variable domain. A complementary determining region (CDR) different from the CDR belonging to the natural antibody ex Camelidae can be grafted on the framework of the variable domain of the heavy chain immunoglobulin. The catalytic antibodies can be raised in Camelidae against transition state molecules.

Abstract: A process is provided for the production of an antibody or a fragment or functionalized fragment thereof using a transformed lower eukaryotic host containing an expressible DNA sequence encoding the antibody or (functionalized) fragment thereof, wherein the antibody or (functionalized) fragment thereof is derived from a heavy chain immunoglobulin of Camelidae and is devoid of light chains, and wherein the lower eukaryotic host is a mould, preferably belonging to the genera Aspergillus or Trichoderma, or a yeast, preferably belonging to the yeast genera Saccharomyces, Kluyveromyces, Hansenula, or Pichia. The heavy chain fragment can contain at least the whole variable domain. A complementary determining region (CDR) different from the CDR belonging to the natural antibody ex Camelidae can be grafted on the framework of the variable domain of the heavy chain immunoglobulin. The catalytic antibodies can be raised in Camelidae against transition state molecules.