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.

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.

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.

A family of alicyclic hydrocarbons containing an amine group with the general formula R-C6H10NH2.

Polyamines are organic compounds with more than one amino group, involved in various biological processes such as cell growth, differentiation, and apoptosis, and found to be increased in certain diseases including cancer.

A toxic diamine formed by putrefaction from the decarboxylation of arginine and ornithine.

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.

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.

Nucleosides in which the base moiety is substituted with one or more sulfur atoms.

Transferases are enzymes transferring a group, for example, the methyl group or a glycosyl group, from one compound (generally regarded as donor) to another compound (generally regarded as acceptor). The classification is based on the scheme "donor:acceptor group transferase". (Enzyme Nomenclature, 1992) EC 2.

An inhibitor of ORNITHINE DECARBOXYLASE, the rate limiting enzyme of the polyamine biosynthetic pathway.

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.

Adenosine molecules which can be substituted in any position, but are lacking one hydroxyl group in the ribose part of the molecule.

Organic chemicals which have two amino groups in an aliphatic chain.

Propylamines are organic compounds consisting of an amino group (-NH2) attached to a propyl group (CH3CH2CH2-), which can act as central nervous system stimulants, local anesthetics, or vasopressors, depending on their specific chemical structure.

5'-S-(3-Amino-3-carboxypropyl)-5'-thioadenosine. Formed from S-adenosylmethionine after transmethylation reactions.

Physiologic methyl radical donor involved in enzymatic transmethylation reactions and present in all living organisms. It possesses anti-inflammatory activity and has been used in treatment of chronic liver disease. (From Merck, 11th ed)

A group of dominantly and independently inherited antigens associated with the ABO blood factors. They are glycolipids present in plasma and secretions that may adhere to the erythrocytes. The phenotype Le(b) is the result of the interaction of the Le gene Le(a) with the genes for the ABO blood groups.

Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).

A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.

The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.

Immunoglobulins produced in response to VIRAL ANTIGENS.

Antibodies produced by a single clone of cells.

Immunoglobulins produced in a response to BACTERIAL ANTIGENS.