Cross-linking of Fbn in the absence of FXIII-B.
A–E, FXIII-A or FXIII-B was removed from normal human plasma using anti-FXIII-A or -B antibody-Sepharose. Cross-linking reactions were performed in normal (A), FXIII-A-depleted (B), and FXIII-B-depleted plasma (C) with or without the addition of rFXIII-A and rFXIII-B. Monomer and dimer of γ-chain in FXIII-A-depleted (D) and FXIII-B-depleted plasma (E) were quantified by a densitometer, and γ-γ dimer formation was calculated as dimer/(monomer + dimer). The mean of three independent experiments was plotted. Dotted line, no addition; filled triangle, FXIII-A-depleted plasma with rFXIII-A; open square, FXIII-B-depleted plasma with rFXIII-A; filled square, FXIII-B-depleted plasma with rFXIII-A and rFXIII-B, error bars, S.D. F and G, purified human Fbg was reacted with thrombin in the presence of rFXIII-A without or with rFXIII-B. Densitometric analyses of γ-γ dimer formation in three independent experiments were performed. Open circle, Fbg with rFXIII-A; filled circle, Fbg with rFXIII-A and rFXIII-B. *, p < 0.05; **, p < 0.01; ***, p < 0.001.