Biomaterial Database

Multiple active conformers of mouse ornithine decarboxylase. 1993

S E Tsirka, and C W Turck, and P Coffino

Department of Microbiology and Immunology, University of California San Francisco 94143.

Purified recombinant mouse ornithine decarboxylase (ODC) was denatured with urea or with guanidinium chloride. Enzymic activity was efficiently recovered upon dilution of the denaturing agent. ODC renatured after urea treatment was further characterized. Kinetics of decarboxylation of the natural substrate ornithine or of the suicide substrate alpha-difluoromethylornithine (DFMO) were not significantly changed by denaturation/renaturation. Surprisingly, the renatured enzyme was not stably labelled with radioactive DFMO, in contrast with the native enzyme not subjected to denaturation. Native and renatured ODC did not differ in their c.d. spectra, but the former contained four reactive cysteine residues and the latter seven. These data indicate that a conformational change results from denaturation/renaturation that does not alter decarboxylation of substrates, but does change the accessibility or stability of the cysteine-360 residue modified by decarboxylated DFMO.

UI	MeSH Term	Description	Entries
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D009955	Ornithine Decarboxylase	A pyridoxal-phosphate protein, believed to be the rate-limiting compound in the biosynthesis of polyamines. It catalyzes the decarboxylation of ornithine to form putrescine, which is then linked to a propylamine moiety of decarboxylated S-adenosylmethionine to form spermidine.	Ornithine Carboxy-lyase,Carboxy-lyase, Ornithine,Decarboxylase, Ornithine,Ornithine Carboxy lyase
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D011489	Protein Denaturation	Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.	Denaturation, Protein,Denaturations, Protein,Protein Denaturations
D011994	Recombinant Proteins	Proteins prepared by recombinant DNA technology.	Biosynthetic Protein,Biosynthetic Proteins,DNA Recombinant Proteins,Recombinant Protein,Proteins, Biosynthetic,Proteins, Recombinant DNA,DNA Proteins, Recombinant,Protein, Biosynthetic,Protein, Recombinant,Proteins, DNA Recombinant,Proteins, Recombinant,Recombinant DNA Proteins,Recombinant Proteins, DNA
D003653	Decarboxylation	The removal of a carboxyl group, usually in the form of carbon dioxide, from a chemical compound.	Decarboxylations
D006146	Guanidines	A family of iminourea derivatives. The parent compound has been isolated from mushrooms, corn germ, rice hulls, mussels, earthworms, and turnip juice. Derivatives may have antiviral and antifungal properties.
D000518	Eflornithine	An inhibitor of ORNITHINE DECARBOXYLASE, the rate limiting enzyme of the polyamine biosynthetic pathway.	Difluoromethylornithine,alpha-Difluoromethylornithine,DL-alpha-Difluoromethylornithine,Eflornithine Hydrochloride,Eflornithine Monohydrochloride, Monohydrate,MDL-71,782 A,Ornidyl,RMI 71782,Vaniqa,alpha-Difluoromethyl Ornithine,DL alpha Difluoromethylornithine,MDL 71,782 A,MDL71,782 A,Ornithine, alpha-Difluoromethyl,alpha Difluoromethyl Ornithine,alpha Difluoromethylornithine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining