Formation of lactate dehydrogenase complexes with proteins and polyelectrolytes. A possible physiological role

The effect of polymers (proteins, polyaminoacids, polyethylenimine) on kinetic parameters of lactate dehydrogenase (LDH) from porcine skeletal muscle was studied. Activation of the enzyme which was partially due to the association of LDH dimers was observed. A hypothesis was proposed, according to which the contribution of dissociation of oligomeric enzymes in the regulation of their activity in vivo is negligible due to the equilibrium shift towards association in dissociable enzyme systems.     

Synthesis of recombinant gamma interferons resistant to proteolysis in the yeast Pichia pastoris

Genes encoding truncated versions of bovine and chicken gamma interferon genes lacking predicted protease cleavage sites at the C-terminus were constructed and expressed in the yeast Pichia pastoris. The recombinant proteins possessed increased stability in comparison with the corresponding wild-type gamma interferons while retaining biological activity. The recombinant strains provide a useful tool for the purification of bovine and chicken gamma interferons for their use in veterinary applications.