Putrescine: A toxic diamine formed by putrefaction from the decarboxylation of arginine and ornithine.PolyaminesSpermidine: 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.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.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.Eflornithine: An inhibitor of ORNITHINE DECARBOXYLASE, the rate limiting enzyme of the polyamine biosynthetic pathway.Ornithine: An amino acid produced in the urea cycle by the splitting off of urea from arginine.Adenosylmethionine Decarboxylase: An enzyme that catalyzes the decarboxylation of S-adenosyl-L-methionine to yield 5'-deoxy-(5'-),3-aminopropyl-(1), methylsulfonium salt. It is one of the enzymes responsible for the synthesis of spermidine from putrescine. EC 4.1.1.50.Cadaverine: A foul-smelling diamine formed by bacterial decarboxylation of lysine.Agmatine: Decarboxylated arginine, isolated from several plant and animal sources, e.g., pollen, ergot, herring sperm, octopus muscle.Biogenic Polyamines: Biogenic amines having more than one amine group. These are long-chain aliphatic compounds that contain multiple amino and/or imino groups. Because of the linear arrangement of positive charge on these molecules, polyamines bind electrostatically to ribosomes, DNA, and RNA.Diamines: Organic chemicals which have two amino groups in an aliphatic chain.Mitoguazone: Antineoplastic agent effective against myelogenous leukemia in experimental animals. Also acts as an inhibitor of animal S-adenosylmethionine decarboxylase.Spermidine Synthase: An enzyme that catalyzes the transfer of the propylamine moiety from 5'-deoxy-5'-S-(3-methylthiopropylamine)sulfonium adenosine to putrescine in the biosynthesis of spermidine. The enzyme has a molecular weight of approximately 73,000 kDa and is composed of two subunits of equal size.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.UreohydrolasesButylaminesAmine Oxidase (Copper-Containing): A group of enzymes including those oxidizing primary monoamines, diamines, and histamine. They are copper proteins, and, as their action depends on a carbonyl group, they are sensitive to inhibition by semicarbazide.Cyclohexylamines: A family of alicyclic hydrocarbons containing an amine group with the general formula R-C6H10NH2.Carboxyl and Carbamoyl Transferases: A group of enzymes that catalyze the transfer of carboxyl- or carbamoyl- groups. EC 2.1.3.Oxidoreductases Acting on CH-NH Group Donors: Enzymes catalyzing the dehydrogenation of secondary amines, introducing a C=N double bond as the primary reaction. In some cases this is later hydrolyzed.Amines: A group of compounds derived from ammonia by substituting organic radicals for the hydrogens. (From Grant & Hackh's Chemical Dictionary, 5th ed)Spermine Synthase: An enzyme that catalyzes the transfer of the propylamine moiety from 5'-deoxy-5'-S-(3-methylthiopropylamine)sulfonium adenosine to spermidine in the biosynthesis of spermine. It has an acidic isoelectric point at pH 5.0. EC 2.5.1.22.Datura stramonium: A plant species of the genus DATURA, family SOLANACEAE, that contains TROPANES and other SOLANACEOUS ALKALOIDS.Kinetics: The rate dynamics in chemical or physical systems.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.Transglutaminases: Transglutaminases catalyze cross-linking of proteins at a GLUTAMINE in one chain with LYSINE in another chain. They include keratinocyte transglutaminase (TGM1 or TGK), tissue transglutaminase (TGM2 or TGC), plasma transglutaminase involved with coagulation (FACTOR XIII and FACTOR XIIIa), hair follicle transglutaminase, and prostate transglutaminase. Although structures differ, they share an active site (YGQCW) and strict CALCIUM dependence.Acetyltransferases: Enzymes catalyzing the transfer of an acetyl group, usually from acetyl coenzyme A, to another compound. EC 2.3.1.Leukemia L1210Ornithine Carbamoyltransferase: A urea cycle enzyme that catalyzes the formation of orthophosphate and L-citrulline (CITRULLINE) from CARBAMOYL PHOSPHATE and L-ornithine (ORNITHINE). Deficiency of this enzyme may be transmitted as an X-linked trait. EC 2.1.3.3.Arginine: An essential amino acid that is physiologically active in the L-form.Propylamines