title: Characterization of factor XII Tenri, a rare CRM-negative factor XII deficiency.
abstract: Factor XII Tenri (Y34C), a rare cross-reacting material (CRM)-negative factor XII deficiency, was identified in a 71-yr-old Japanese woman with angina pectoris. In the patient's plasma, factor XII activity and antigen levels were only 1.6% and 5.0%, respectively, of those seen in a normal subject. Immunoblot analysis showed that the secreted factor XII Tenri existed not only as a monomer (76 kDa), but also in complexes with apparent molecular weights of approximately 115, 140, 190, 215, and 225 kDa. After reduction with 2-mercaptoethanol, the factor XII Tenri contained in the complexes was completely converted to monomeric form on immunoblot patterns. It appeared that some of the secreted factor XII Tenri formed several types of disulfide-linked complexes, including a factor XII-alpha1-microglobulin complex, through a newly generated Cys residue. The monomeric form of factor XII Tenri, like normal factor XII, was degraded into 2 major fragments with molecular weights of approximately 45 kDa and 30 kDa following mixing with activated partial-thromboplastin-time measuring reagent (cephalin and ellagic acid), whereas the factor XII Tenri that formed the complexes was not. This indicates that the factor XII Tenri present in disulfide-linked complexes with other proteins (and itself) is not converted to active forms, suggesting that attached proteins obstruct or delay the activation of factor XII via an inhibition of its binding to a negatively charged surface in vitro.
authors.affiliation: Department of Laboratory Medicine, Shinshu University Hospital, Matsumoto, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Fujihara
authors.forename: Minoru
authors.initials: M
authors.lastname: Tozuka
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Yamauchi
authors.forename: Ichiro
authors.initials: I
authors.lastname: Ueno
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Urasawa
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Ishikawa
authors.forename: Masako
authors.initials: M
authors.lastname: Hirota-Kawadobora
authors.forename: Nobuo
authors.initials: N
authors.lastname: Okumura
authors.forename: Hiroya
authors.initials: H
authors.lastname: Hidaka
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Katsuyama
mesh_terms: D000368:Aged; D000941:Antigens / Q000097:blood; D001483:Base Sequence; D005174:Factor XII / Q000032:analysis / Q000235:genetics*; D005175:Factor XII Deficiency / Q000097:blood / Q000235:genetics*; D005260:Female; D006801:Humans; D008969:Molecular Sequence Data; D010314:Partial Thromboplastin Time; D011110:Polymorphism, Genetic
chemical_list: D000941:Antigens; D005174:Factor XII