Evidence for the presence of a kininogen-like species in a case of total deficiency of low and high molecular weight kininogens
Braz. j. med. biol. res
;
31(7): 901-10, jul. 1998. ilus
Article
in English
| LILACS
| ID: lil-212875
ABSTRACT
Low and high molecular weight kininogens (LK and HK), containing 409 and 626 amino acids with masses of ~65 and 120120 kDa after glycosylation, respectively, are coded by a single gene mapped to the human chromosome 3 by alternative splicing of the transcribed mRNA. The NH2-termini Glu(1)-Thr(383) region, identical in LK and HK, contains bradykinin (BK) moieties Arg(363)-Arg(371). LK, HK and their kinin products Lys-BK and BK are involved in several biological processes. They are evolutionarily conserved and only 7 patients, all apparently normal, have been reported to lack them. In one of these patients (Williams'trait), a codon mutation (Arg(178) r stop) has been blamed for the absence of LK and HK. However, using Western blots with 2 monoclonal anti-HK antibodies, one that recognizes the region common to LK and HK and the other that recognizes only HK, I detected ~110-kDa bands in the plasma of this LK/HK-deficient patient vs ~120-kDa bands in normal human and ape plasmas. With polyclonal anti-Lys-BK antibody, which strongly detects BK eleaved at its COOH-terminus in purified HK, I detected ~110-kDa bands in the normal and the deficient plasmas. Western blots with a monoclonal anti-prekallikrein (PK) antibody showed that surface activation of PK and distribution of PK activation products, both dependent on HK, were similar in these plasmas. These findings suggest that a mutant gene yielded a kininogen-like species possibly involving aberrant mRNA splicing - structurally different from normal HK, but apparently with the capacity to carry out seemingly vital HK functions.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Plasma
/
Blood Coagulation Disorders
/
Kininogens
/
Kininogen, High-Molecular-Weight
/
Kininogen, Low-Molecular-Weight
Limits:
Female
/
Humans
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
1998
Type:
Article
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