ChemFOnt: Showing chemical card for Selenocystine (CFc000002064)

Record Information

Version

1.0

Creation Date

2022-08-28 10:25:12 UTC

Update Date

2022-09-13 18:46:51 UTC

Chemfont ID

CFc000002064

Molecule Identification

Common Name

Selenocystine

Definition

Selenocystine, also known as 3,3'-diselenodialanine, belongs to the class of organic compounds known as alpha-amino acids. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxyl group (alpha carbon). More specifically, selenocystine is a diselenide consisting of two selenoamino acids that are attached together at their selenium atoms. This particular selenoamino acid is selenocysteine, the selenium analogue to cysteine (selenium being the element directly beneath sulphur in the periodic table); likewise, selenocystine is the selenium analogue to cystine. Since each constituent amino acid has a stereocentre, there are three different stereoisomers of selenocystine: D-selenocystine, L-selenocystine, and meso-selenocystine, the first two of which are optically active. Like other amino acids, L-selenocystine is the most common form within organisms; however, the D- and meso- forms have also been found (PMID: 30920149 ). Selenocystine is a solid that is moderately soluble in water. Due to the reactivity of selenocysteine, it is rarely encountered; rather, cells store selenium in the less reactive oxidized form of selenocystine or in a methylated form, such as selenomethionine (DOI: 10.1007/978-3-319-92405-2_3). When cells are grown in the absence of selenium, translation of selenoproteins terminates at the UGA codon, resulting in a truncated, non-functional enzyme. Unlike other amino acids present in biological proteins, selenocysteine is not coded for directly in the genetic code. Rather, the tRNA-bound seryl residue is converted to a selenocysteine residue by the pyridoxal phosphate-containing enzyme selenocysteine synthase (PMID: 17194211 ). Kurt Franke et al. indicated that there was evidence that selenium was in a form similar to that of cysteine, predating Thressa Stadtman’s discovery of the 21st amino acid by four decades (PMID: 26949981 ; J. Biol. Chem. 111:643). Selenocysteine may be denoted by the short forms Sec, U, or SeCys (Cys is used for cysteine), whereas selenocystine may be denoted by SeCys2. However, the literature sometimes uses SeCys for selenocystine and may cause confusion. Selenocystine has been found in animals, plants, and bacteria. It is being researched as treatment for cancer and for its antioxidant properties (PMID: 24763048 , 24030774 ). Selenium, in its various forms such as selenocystine, is essential for many species, including humans, yet it is also toxic to all organisms; hence, it has come to be referred to as the “essential poison” (PMID: 26949981 ; 6679541).

Structure

MOL SDF PDB SMILES InChI

Synonyms

Value	Source
3,3'-Diselenobisalanine	ChEBI
3,3'-Diselenodialanine	ChEBI
Selenocystine, (D)-isomer	MeSH
Selenocystine, (DL)-isomer	MeSH
Selenocystine, (L)-isomer	MeSH
D,L-Selenocystine	HMDB
DL-Selenocystine	HMDB
Selenium cystine	HMDB
seleno-DL-Cystine	HMDB

Chemical Formula

C₆H₁₂N₂O₄Se₂

Average Molecular Weight

334.09

Monoisotopic Molecular Weight

335.912750538

IUPAC Name

2-amino-3-[(2-amino-2-carboxyethyl)diselanyl]propanoic acid

Traditional Name

selenocystine

CAS Registry Number

1464-43-3

SMILES

NC(C[Se][Se]CC(N)C(O)=O)C(O)=O

InChI Identifier

InChI=1S/C6H12N2O4Se2/c7-3(5(9)10)1-13-14-2-4(8)6(11)12/h3-4H,1-2,7-8H2,(H,9,10)(H,11,12)

InChI Key

JULROCUWKLNBSN-UHFFFAOYSA-N

Chemical Taxonomy

Description

Belongs to the class of organic compounds known as alpha amino acids. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon).

Kingdom

Organic compounds

Super Class

Organic acids and derivatives

Class

Carboxylic acids and derivatives

Sub Class

Amino acids, peptides, and analogues

Direct Parent

Alpha amino acids

Alternative Parents

Substituents

Alpha-amino acid
Dicarboxylic acid or derivatives
Diselenide group
Amino acid
Carboxylic acid
Hydrocarbon derivative
Primary amine
Organoselenium compound
Organooxygen compound
Organonitrogen compound
Primary aliphatic amine
Organopnictogen compound
Organic oxygen compound
Carbonyl group
Amine
Organic nitrogen compound
Organic oxide
Aliphatic acyclic compound

Molecular Framework

Aliphatic acyclic compounds

External Descriptors

selenoamino acid (CHEBI:28553 )
diselenide (CHEBI:28553 )

Functional Ontology

Physiological effect

Not Available

Disposition

Biological location

Non-excretory biofluid

Biofluid or Excreta

Blood (PMID: 15595669)

Cellular substructure

Cytoplasm (HMDB: HMDB0004122)

Source

Endogenous

Endogenous (HMDB: HMDB0004122)

Pheasant (FooDB: FOOD00430)
Squab (FooDB: FOOD00481)
Turkey (FooDB: FOOD00494)
Quail (FooDB: FOOD00541)
Anatidae (FooDB: FOOD00576)
Rock ptarmigan (FooDB: FOOD00597)
Columbidae (Dove, Pigeon) (FooDB: FOOD00610)
Chicken (FooDB: FOOD00329)
Mallard duck (FooDB: FOOD00353)
Emu (FooDB: FOOD00360)
Greylag goose (FooDB: FOOD00368)
Guinea hen (FooDB: FOOD00373)
Ostrich (FooDB: FOOD00422)
Velvet duck (FooDB: FOOD00427)

Lagomorph

Ovis

Sheep (Mutton, Lamb) (FooDB: FOOD00473)

Bovine

Venison

Deer (FooDB: FOOD00524)
Mule deer (FooDB: FOOD00348)
Elk (FooDB: FOOD00359)

Caprae

Domestic goat (FooDB: FOOD00529)

Swine

Domestic pig (FooDB: FOOD00536)
Wild boar (FooDB: FOOD00307)

Equine

Horse (FooDB: FOOD00378)

Process

Naturally occurring process

Biological process

Biochemical pathway

Metabolic pathway

Selenoamino Acid Metabolism (PathBank: SMP0063587)
Selenoamino Acid Metabolism (HMDB: HMDB0004122)

Role

Not Available

Physical Properties

Predicted Properties

Property	Value	Source
Water Solubility	50.7 g/L	ALOGPS
logP	-3.9	ALOGPS
logP	-7.9	ChemAxon
logS	-0.82	ALOGPS
pKa (Strongest Acidic)	0.64	ChemAxon
pKa (Strongest Basic)	8.61	ChemAxon
Physiological Charge	0	ChemAxon
Hydrogen Acceptor Count	8	ChemAxon
Hydrogen Donor Count	4	ChemAxon
Polar Surface Area	126.64 Å²	ChemAxon
Rotatable Bond Count	7	ChemAxon
Refractivity	65.51 m³·mol⁻¹	ChemAxon
Polarizability	20.49 Å³	ChemAxon
Number of Rings	0	ChemAxon
Bioavailability	Yes	ChemAxon
Rule of Five	Yes	ChemAxon
Ghose Filter	No	ChemAxon
Veber's Rule	No	ChemAxon
MDDR-like Rule	No	ChemAxon