Octopine is a
derivative
In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. ...
of the
amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha ...
s
arginine
Arginine is the amino acid with the formula (H2N)(HN)CN(H)(CH2)3CH(NH2)CO2H. The molecule features a guanidino group appended to a standard amino acid framework. At physiological pH, the carboxylic acid is deprotonated (−CO2−) and both the a ...
and
alanine
Alanine (symbol Ala or A), or α-alanine, is an α-amino acid that is used in the biosynthesis of proteins. It contains an amine group and a carboxylic acid group, both attached to the central carbon atom which also carries a methyl group side ...
. It was the first member of the class of chemical compounds known as
opines
Opines are low molecular weight compounds found in plant crown gall tumors or hairy root tumors produced by pathogenic bacteria of the genus ''Agrobacterium'' and '' Rhizobium''. Opine biosynthesis is catalyzed by specific enzymes encoded by ge ...
to be discovered. Octopine gets its name from ''
Octopus octopodia
The common octopus (''Octopus vulgaris'') is a mollusc belonging to the class Cephalopoda. ''Octopus vulgaris'' is one of the most studied of all octopus species, and also one of the most intelligent. It ranges from the eastern Atlantic, extends ...
'' from which it was first isolated in 1927.
Octopine has been isolated from the muscle tissue of invertebrates such as
octopus
An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefis ...
, ''
Pecten maximus
''Pecten maximus'', common names the great scallop, king scallop, St James shell or escallop, is a northeast Atlantic species of scallop, an edible saltwater clam, a marine bivalve mollusc in the family Pectinidae. This is the type species of ...
'' and ''
Sipunculus nudus
''Sipunculus nudus'' is a cosmopolitan species of unsegmented marine worm of the phylum Sipuncula, also known as peanut worms.
Description
As in all peanut worms, the body of ''S. nudus'' consists of a sac-like portion called the trunk and an eve ...
'' where it functions as an analog of
lactic acid
Lactic acid is an organic acid. It has a molecular formula . It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as well as natur ...
. Plants may also produce this compound after
infection
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable d ...
by ''
Agrobacterium tumifaciens'' and transfer of the octopine synthesis gene from the bacterium to the plant.
Octopine is formed by reductive
condensation
Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor ...
of
pyruvic acid
Pyruvic acid (CH3COCOOH) is the simplest of the alpha-keto acids, with a carboxylic acid and a ketone functional group. Pyruvate, the conjugate base, CH3COCOO−, is an intermediate in several metabolic pathways throughout the cell.
Pyruvic ac ...
and arginine through the action of the
NADH
Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an aden ...
-dependent enzyme
octopine dehydrogenase (ODH).
The reaction is reversible so that pyruvic acid and arginine can be regenerated.
:
References
{{reflist
Amino acid derivatives
Dicarboxylic acids
Guanidines