TY - JOUR
T1 - Direct characterization of factor VIII in plasma
T2 - Detection of a mutation altering a thrombin cleavage site (arginine-372 → histidine)
AU - Arai, M.
AU - Inaba, H.
AU - Higuchi, M.
AU - Antonarakis, S. E.
AU - Kazazian, H. H.
AU - Fujimaki, M.
AU - Hoyer, L. W.
PY - 1989
Y1 - 1989
N2 - An immunoadsorbent method has been developed for the direct analysis of normal and variant plasma factor VIII. Using this method, the molecular defect responsible for mild hemophilia A has been identified for a patient whose plasma factor VIII activity is 0.05 unit/ml, even though the factor VIII antigen content is 3.25 units/ml. Although the variant factor VIII has an apparently normal molecular mass and chain composition, the 92-kDa heavy chain accumulates when the variant protein is incubated with thrombin and the 44-kDa heavy chain fragment cannot be detected. In contrast, thrombin cleavage of the 80-kDa light chain to the 72-kDa fragment is normal. As these data indicate a loss of factor VIII cleavage by thrombin at arginine-372, the genetic defect was determined by polymerase-chain-reaction amplification of exon 8 of the factor VIII gene and direct sequencing of the amplified product. A single-base substitution (guanine → adenine) was identified that produces an arginine to histidine substitution at amino acid residue 372. These data identify the molecular basis of an abnormal factor VIII, 'factor VIII-Kumamoto', that lacks procoagulant function because of impaired thrombin activation.
AB - An immunoadsorbent method has been developed for the direct analysis of normal and variant plasma factor VIII. Using this method, the molecular defect responsible for mild hemophilia A has been identified for a patient whose plasma factor VIII activity is 0.05 unit/ml, even though the factor VIII antigen content is 3.25 units/ml. Although the variant factor VIII has an apparently normal molecular mass and chain composition, the 92-kDa heavy chain accumulates when the variant protein is incubated with thrombin and the 44-kDa heavy chain fragment cannot be detected. In contrast, thrombin cleavage of the 80-kDa light chain to the 72-kDa fragment is normal. As these data indicate a loss of factor VIII cleavage by thrombin at arginine-372, the genetic defect was determined by polymerase-chain-reaction amplification of exon 8 of the factor VIII gene and direct sequencing of the amplified product. A single-base substitution (guanine → adenine) was identified that produces an arginine to histidine substitution at amino acid residue 372. These data identify the molecular basis of an abnormal factor VIII, 'factor VIII-Kumamoto', that lacks procoagulant function because of impaired thrombin activation.
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U2 - 10.1073/pnas.86.11.4277
DO - 10.1073/pnas.86.11.4277
M3 - Article
C2 - 2498882
AN - SCOPUS:0005924558
SN - 0027-8424
VL - 86
SP - 4277
EP - 4281
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 11
ER -