Thromb Haemost 1988; 60(03): 476-480
DOI: 10.1055/s-0038-1646994
Original Article
Schattauer GmbH Stuttgart

Normal Plasmic Cleavage of the γ-Chain Variant of “Fibrinogen Saga” with an Arg–275 to His Substitution

Kensuke Yamazumi
The Division of Hemostasis and Thrombosis Research, Institute of Hematology, Jichi Medical School, Tochigi-Ken, Japan
,
Michio Matsuda
The Division of Hemostasis and Thrombosis Research, Institute of Hematology, Jichi Medical School, Tochigi-Ken, Japan
,
Shigeharu Terukina
The Division of Hemostasis and Thrombosis Research, Institute of Hematology, Jichi Medical School, Tochigi-Ken, Japan
,
Shingo Onohara
1   The Department of Internal Medicine, Saga Prefectural Hospital, Saga, Japan
› Author Affiliations
Further Information

Publication History

Received 15 March 1988

Accepted after revision 08 August 1988

Publication Date:
23 July 2018 (online)

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Summary

We have identified a γ-Arg–275 to His substitution in an abnormal fibrinogen designated as “fibrinogen Saga” characterized by impaired fibrin monomer polymerization. By chromatofocusing chromatography, we isolated normal and abnormal fragment Dl populations separately from the plasmic-calcium digests of fibrinogen derived from the propositus, a heterozygote for the abnormality. We found that both normal and abnormal fragment D1’s were similarly protected from digestion by plasmin in the presence of calcium ions and further degraded to fragments D2 and D3 due to cleavage of the γ-chain remnant when calcium ions were replaced by chelating agents. Abnormal fragment D1 failed to inhibit both thrombin-clotting of normal fibrinogen and polymerization of normal fibrin monomer, while normal D1 exhibited marked inhibitory activities. In an aberrant peptide comprising residues γ–274–302 isolated by HPLC from the lysyl endopeptidase-digests of abnormal fragment D1, we identified a His substituting for an Arg at position 2, which corresponds to position 275 of the mutant γ-chain