Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1989-2-7
pubmed:abstractText
Factor XIII is a transglutaminase important in blood coagulation and fibrinolysis. Its function is to catalyze peptide bond formation between the gamma-carboxamide group of glutamines in one protein and the epsilon-amino group of lysine in another. There are two zymogenic forms of factor XIII: one is a noncovalent, intracellular dimer (A2); the other is a noncovalent, extracellular tetramer (A2B2). The catalytic function resides in the activated A chain (A2.). Purified forms of factor XIII (A2B2, A2, A2.B2, B) were prepared and analyzed by electron microscopy, gel filtration, and gradient centrifugation. Hydrodynamic constants were derived. Electron microscopy of rotary-shadowed molecules showed A2 to consist of two globular particles each about 6 x 9 nm in size. The A2 dimer is significantly elongated, 18 nm long and 6 nm in diameter. Sedimentation and gel filtration of the A2 dimer are consistent with this asymmetric structure. B protein is a filamentous, flexible strand with kinks, with a contour length of 30 nm and a diameter of approximately 2-3 nm. The sedimentation and gel filtration behavior of the B subunit are characteristic of a highly asymmetric molecule. The observed structure of the B subunit, combined with data for its amino acid sequence, suggests a modular structure. The B subunit is a member of a family of proteins composed of tandem, repeating structures (referred to as GP-I domains); the structure seen by electron microscopy for B subunit is probably applicable to all proteins in this family. Plasma and platelet factor XIII zymogens are tetrameric and dimeric, but B protein, in the absence of A protein, appears to be monomeric. Our model for the A2B2 zymogen has the elongated A2 dimer forming the core and the two B strands wrapping around the outside.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
264
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
551-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Electron microscopy and hydrodynamic properties of factor XIII subunits.
pubmed:affiliation
Department of Anatomy, Duke University Medical Center, Durham, North Carolina 22710.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.