Title: Bradykinin
CAS Registry Number: 58-82-2
Additional Names: Kallidin I; kallidin-9; callidin I
Manufacturers' Codes: BRS-640
Molecular Formula: C50H73N15O11
Molecular Weight: 1060.21
Percent Composition: C 56.64%, H 6.94%, N 19.82%, O 16.60%
Literature References: A tissue hormone belonging to a group of hypotensive peptides known as plasma kinins. First obtained by incubation with the venom of Bothrops jararaca or with crystalline trypsin: Rocha e Silva et al., Cien Cult. (Sao Paulo) 1, 32 (1949); eidem, Am. J. Physiol. 156, 261 (1949); Prado et al., Arch. Biochem. 27, 410 (1950); Werle et al., Biochem. Z. 320, 372 (1950). Large scale prepn from whole bovine plasma: Hamberg, Deutsch, Arch. Biochem. Biophys. 76, 262 (1958). Formed by proteolysis of a precursor in the globulin fraction of plasma referred to as kininogen by the action of enzymes such as trypsin, plasmin, and plasma kallikrein, q.q.v. Acts on smooth muscle, dilates peripheral vessels, increases capillary permeability. Also is a potent pain-producing agent. Structure: Elliott et al., Biochem. Biophys. Res. Commun. 3, 87 (1960); Werle et al., Z. Physiol. Chem. 326, 174 (1961). Synthesis: Boissonnas et al., Helv. Chim. Acta 43, 1349 (1960); 45, 170 (1962); Merrifield, Biochemistry 3, 1385 (1964); Young et al., J. Chem. Soc. C 1971, 46; Bajusz et al., HU 3840 (1972 to Gyogyszerkutato Intézet), C.A. 77, 20027g (1972); F. Sipos, DE 2212787; idem, US 3714140 (1972, 1973 both to Squibb); Corley et al., Biochem. Biophys. Res. Commun. 47, 1353 (1972); N. S. S. Kumari et al., Indian J. Chem. 17B, 152 (1979). Review: Schröder, Hempel, Experientia 20, 529 (1964).
Properties: Amorphous precipitate. [a]D25 -76.5° (c = 1.37 in 1N acetic acid). Sol in glacial acetic acid, in a 10% soln of trichloroacetic acid, 70% ethanol, in hot methanol; less sol in 90% ethanol or cold methanol. Almost insol in acetone, chloroform, ethyl ether, ethyl methyl ketone, petr ether, butanol, amyl alcohol, ethyl acetate.
Optical Rotation: [a]D25 -76.5° (c = 1.37 in 1N acetic acid)
Therap-Cat: Vasodilator.
Keywords: Vasodilator (Peripheral).
Brain Natriuretic Peptide Brallobarbital Brandy Brassidic Acid Brassinolide

Bradykinin structure.svg
Bradykinin updated.png
CAS number 58-82-2 YesY
PubChem 439201
ChemSpider 388341 YesY
MeSH Bradykinin
IUPHAR ligand 649
Jmol-3D images Image 1
Molecular formula C50H73N15O11
Molar mass 1060.21 g/mol
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references
kininogen 1
Symbol KNG1
Alt. symbols KNG, BDK
Entrez 3827
HUGO 6383
OMIM 612358
RefSeq NM_001102416
UniProt P01042
Other data
Locus Chr. 3 q21-qter
Symbol Bradykinin
Pfam PF06753
InterPro IPR009608

Bradykinin is a peptide that causes blood vessels to dilate (enlarge), and therefore causes blood pressure to lower. A class of drugs called ACE inhibitors, which are used to lower blood pressure, increase bradykinin (by inhibiting its degradation) further lowering blood pressure. Bradykinin works on blood vessels through the release of prostacyclin, nitric oxide, and Endothelium-Derived Hyperpolarizing Factor.

Bradykinin is a physiologically and pharmacologically active peptide of the kinin group of proteins, consisting of nine amino acids.