Molecular modeling showing the position of the fibrinogen Bβ448 residue in relation to BβAsp398, BβGlu315, and AαLys157. Modeled on Arg (A) and Lys (B) at position 448. Demonstrated are the potential hydrogen bonds (—) from residue Bβ448 and BβLys449 to BβGlu315 and from BβAsp398 to AαLys157 as observed in our simulations. The proximity of the mutation site to areas integral to fibrin polymerization and calcium binding suggests that the potential weakening of hydrogen bonding in this region may have important effects on fibrin structure and function.