Biomaterial Database

Control of ornithine decarboxylase activity in Physarum by polyamines. 1978

J L Mitchell, and D D Carter, and J A Rybski

The addition of putrescine, spermidine, or spermine, to cultures of Physarum polycephalum rapidly reduced the activity of ornithine decarboxylase, with maximal inhibition, 80-90%, occurring after 90 min. This response was not due to a decrease in enzyme molecules, but rather to the rapid conversion of the active enzyme to a stable, catalytically less active form. This response to exogenous polyamines was not accompanied by the appearance of a macromolecular inhibitor (antizyme) either free, or bound to the enzyme. Physiological levels of the polyamines were also found to inhibit this enzyme in vitro both competitively and non-competitively, and to promote complete yet reversible inactivation of this enzyme in the absence of reducing agents. The data suggest that the control of this enzyme by endogenous polyamine levels may be distinct from its response to exogenous polyamines.

UI	MeSH Term	Description	Entries
D010804	Physarum	A genus of protozoa, formerly also considered a fungus. Characteristics include the presence of violet to brown spores.	Physarums
D011073	Polyamines	Amine compounds that consist of carbon chains or rings containing two or more primary amino groups.	Polyamine
D011700	Putrescine	A toxic diamine formed by putrefaction from the decarboxylation of arginine and ornithine.	1,4-Butanediamine,1,4-Diaminobutane,Tetramethylenediamine,1,4 Butanediamine,1,4 Diaminobutane
D002021	Buffers	A chemical system that functions to control the levels of specific ions in solution. When the level of hydrogen ion in solution is controlled the system is called a pH buffer.	Buffer
D002262	Carboxy-Lyases	Enzymes that catalyze the addition of a carboxyl group to a compound (carboxylases) or the removal of a carboxyl group from a compound (decarboxylases). EC 4.1.1.	Carboxy-Lyase,Decarboxylase,Decarboxylases,Carboxy Lyase,Carboxy Lyases
D004229	Dithiothreitol	A reagent commonly used in biochemical studies as a protective agent to prevent the oxidation of SH (thiol) groups and for reducing disulphides to dithiols.	Cleland Reagent,Cleland's Reagent,Sputolysin,Clelands Reagent,Reagent, Cleland,Reagent, Cleland's
D013095	Spermidine	A polyamine formed from putrescine. It is found in almost all tissues in association with nucleic acids. It is found as a cation at all pH values, and is thought to help stabilize some membranes and nucleic acid structures. It is a precursor of spermine.
D013096	Spermine	A biogenic polyamine formed from spermidine. It is found in a wide variety of organisms and tissues and is an essential growth factor in some bacteria. It is found as a polycation at all pH values. Spermine is associated with nucleic acids, particularly in viruses, and is thought to stabilize the helical structure.
D065108	Ornithine Decarboxylase Inhibitors	Substances and drugs that inhibit or block the activity of ORNITHINE DECARBOXYLASE.	Decarboxylase Inhibitors, Ornithine,Inhibitors, Ornithine Decarboxylase