Studies on the structural abnormality of fibrinogen Paris I.

Abstract

A B S T R A C T The structural properties of an inherited fibrinogen abnormality designated fibrinogen Paris I were investigated. Dodecyl sulfate gel electrophoresis of unreduced samples revealed no discernible differences in molecular weight from normal; this implied that in fibrinogen Paris I, the normal fibrinogen architecture of six covalently linked chains per molecule is preserved. Examination of dithiothreitol reduced samples before and after treatment with Reptilase or thrombin revealed that the Aa-and BP-chains could release the A and B peptides, respectively. A mutant chain (mol wt 52,500, termed 'Paris I) which replaces a large proportion of 'v-chains (mol wt 49,400) was shown, like normal 'v-chains, to lack thrombin-and Reptilase-sensitive sites.The a-chains and a-chains of Paris I fibrin underwent Factor XIIIa-catalyzed cross-linking slowly; this behavior was not attributable to an intrinsic abnormality of these chains themselves but rather to the inhibitory effect of the mutant 'vParis I chains on this process. Results of DEAE-cellulose gradient elution chromatography of Paris I fibrinogen preparations revealed the presence of small amounts of normal fibrinogen molecules and also indicated that the 'Paris I chains possessed structural overlap with '-chains. Unlike 'v-chains however, the 'yParis I chains did not incorporate dansylcadaverine in the presence of Factor XIIIa, nor, as previously reported, did they undergo cross-linking. The observations indicate that the amine acceptor site found in the COOHterminal region of the 'v-chain is either not present on the 'vParis I chain or is unavailable for cross-linking. Further support for localization of the abnormality in the COOH-terminal region of the molecule was obtained from the observation that during plasmic hydrolysis of Paris I fibrinogen, at least one unique form of core Fragment D (DParis I) was evolved, whereas Fragment E did not differ from normal.

Human plasma fibrinogen heterogeneity: evidence for an extended carboxyl-terminal sequence in a normal gamma chain variant (gamma').

“…Crosslinking of fibrin was carried out under the following conditions: fibrinogen, 0.5-3 mg/ml; cysteine-HCI (adjusted to pH 7.4 with Tris), 7-10 mM; Ca2 , [15][16][17][18][19][20][21][22][23][24][25] (15,16).…”

“…However, close inspection indicated that the peak 2 -y chain position band usually was somewhat broader than that of peak 1. By varying the conditions of electrophoresis (e.g., 10% acrylamide, 4 mA per gel, 16 hr; see gels 9 and 10), the relative broadness of the peak 2 y chain band could be more easily appreciated. Occasionally, it even could be resolved into two bands, although sharp definition was never obtained.…”

Fibrinogen Philadelphia, a hypodysfibrinogenemia characterized by abnormal polymerization and fibrinogen hypercatabolism due to γ S378P mutation

“…Fibrinogen Paris I is structurally characterized by the insertion of 15 amino acids after ␥ Q350, and functionally manifests as a polymerization defect with normal cross-linking of the wild-type ␥ chains and no cross-linking of the ␥ Paris I chains. 35 Analysis of the clot by electron microscopy also reveals abnormal clumps with irregular fibers and frequent terminations. 36 Consistent with such conclusions is the low turbidity at high-salt concentration (Table 1), which has a characteristic effect on lateral aggregation.…”

Fibrinogen Sevilla, a congenital dysfibrinogenemia characterized by an abnormal monomer aggregation and a defective plasmin lysis

“…In fibrinogens Bethesda III [17], Baltimore I [18], Paris II [19], Nancy [20] and Philadelphia [2], the abnormality lies in the elution of the first peak, whereas in Paris I [22], the two fibrinogen peaks emerged later than their presumed counterparts.…”