Biomaterial Database

Chemical modification of gamma-carboxyglutamic acid, the vitamin K-dependent amino acid which binds Ca2+. 1984

P A Price, and C Nelson, and M K Williamson

gamma-Carboxyglutamic acid (Gla), the vitamin K-dependent Ca2+ binding amino acid, can be chemically modified in several specific reactions. Practical outlines of the published procedures for the thermal decarboxylation of Gla to Glu in dry proteins and the specific exchange labeling of the gamma-proton of Gla with tritium are presented. The applications of these procedures in the analysis of the role of Gla residues in Ca2+ binding and in biological activity are also discussed. In addition, the reversible formation of pyro-gamma-carboxyglutamic acid is described for the first time. Pyro-gamma-carboxyglutamic acid is formed from Gla in over 99% yield in a first-order reaction with a half-time of 3.5 h at pH 10 and 110 degrees C. The mass spectrum of the dimethyl ester of the reaction adduct is consistent with pyro-gamma-carboxyglutamic acid and treatment of the reaction adduct with 2 M KOH for 24 h at 110 degrees C quantitatively regenerates Gla. The applications of this reversible reaction to the quantitative analysis of Gla in proteins are discussed.

UI	MeSH Term	Description	Entries
D007553	Isotope Labeling	Techniques for labeling a substance with a stable or radioactive isotope. It is not used for articles involving labeled substances unless the methods of labeling are substantively discussed. Tracers that may be labeled include chemical substances, cells, or microorganisms.	Isotope Labeling, Stable,Isotope-Coded Affinity Tagging,Isotopically-Coded Affinity Tagging,Affinity Tagging, Isotope-Coded,Affinity Tagging, Isotopically-Coded,Isotope Coded Affinity Tagging,Labeling, Isotope,Labeling, Stable Isotope,Stable Isotope Labeling,Tagging, Isotope-Coded Affinity,Tagging, Isotopically-Coded Affinity
D011506	Proteins	Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.	Gene Products, Protein,Gene Proteins,Protein,Protein Gene Products,Proteins, Gene
D011761	Pyrrolidonecarboxylic Acid	A cyclized derivative of L-GLUTAMIC ACID. Elevated blood levels may be associated with problems of GLUTAMINE or GLUTATHIONE metabolism.	5-Oxoproline,Pidolic Acid,Pyroglutamic Acid,5-Ketoproline,5-Oxopyrrolidine-2-Carboxylic Acid,Magnesium Pidolate,Pyroglutamate,Pidolate, Magnesium
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002621	Chemistry	A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
D003653	Decarboxylation	The removal of a carboxyl group, usually in the form of carbon dioxide, from a chemical compound.	Decarboxylations
D005971	Glutamates	Derivatives of GLUTAMIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the 2-aminopentanedioic acid structure.	Glutamic Acid Derivatives,Glutamic Acids,Glutaminic Acids
D014316	Tritium	The radioactive isotope of hydrogen also known as hydrogen-3. It contains two NEUTRONS and one PROTON in its nucleus and decays to produce low energy BETA PARTICLES.	Hydrogen-3,Hydrogen 3
D014812	Vitamin K	A lipid cofactor that is required for normal blood clotting. Several forms of vitamin K have been identified: VITAMIN K 1 (phytomenadione) derived from plants, VITAMIN K 2 (menaquinone) from bacteria, and synthetic naphthoquinone provitamins, VITAMIN K 3 (menadione). Vitamin K 3 provitamins, after being alkylated in vivo, exhibit the antifibrinolytic activity of vitamin K. Green leafy vegetables, liver, cheese, butter, and egg yolk are good sources of vitamin K.
D015055	1-Carboxyglutamic Acid	Found in various tissues, particularly in four blood-clotting proteins including prothrombin, in kidney protein, in bone protein, and in the protein present in various ectopic calcifications.	gamma-Carboxyglutamate,gamma-Carboxyglutamic Acid,3-Amino-1,1,3-propanetricarboxylic Acid,1 Carboxyglutamic Acid,gamma Carboxyglutamate,gamma Carboxyglutamic Acid