... degÆcm2Ædmol)1for fibritin B1 and fibritin SM4, respectively.Interestingly, fibritin M e xhibited more a helicity thanfibritin E, probably due to the absence of insertion loops.The CD spectrum of fibritin F represented ... wild-type fibritin, can be explainedmainly by two residues substitutions. As confirmed by X-ray crystallography [9],the mutation Ser421 to Lyscreated a new salt bridge between residues Lys421 and Glu426. ... enthalpy of the transition f or theE, SM4, SM1 and B1 fibritins increases linearly with anincreasing number of amino-acid r esidues in the coiled-coilregion. In contrast to the independent melting...