Etude de la masse moléculaire de la lactotransferrine et de la serotransferrine humaines

D. LÉGER, A. VERBERT, Marie-Henriette LOUCHEUX, Geneviève SPIK, Myriam CONIEZ, C. DUPIRE, J. P. DECOTTIGNIES
1977 Reproduction nutrition development (Print)  
The molecular weight of human lactotransferrin and serotransferrin. Molecular weight of human lactotransferrin (LTF) has been studied applying several procedures. Human serotransferrin (STF) was used as reference material. Equilibriumsedimentation in non-denaturating (Tris-HCI) and in denaturating (6 M guanidinium chloride) media of 3 forms of LTF and STF (native, reduced, reduced and carboxamidomethylated proteins) led to values of 77 000 ! 1 000 and 75 000 ! 1 000 for LTF and STF,
more » ... nd STF, respectively. These values were confirmed on the basis of iron determinations, gel filtration behaviour, electrophoretic mobilities in polyacrylamide gel, sedimentation coefficient (S°2o ) and intrinsic viscosity. The number of amino acid residues was 641 !-20 for LTF and 632 ! 20 for STF, when estimated from the { 7] values. This number was 646 ! 20 for LTF and 639 ! 20 for STF when calculated on the basis of S 0 20 values obtained with the carboxamidomethylated transferrins in denaturating medium. The 7 to 9 additional amino acid residues and the 5 to 6 supplementary fucose residues in LTF could explain the slightly higher molecular weight of this protein as compared to STF. Moreover, our results confirm the single chain structure of LTF and STF proposed by others and do not agree with the multiple chain structure we suggested previously, in particular on the basis of C-terminal amino acid determination by hydrazinolysis. As is the case of bovine and murine LTF, human LTF led to the formation of oligomeric structures in concentrated aqueous solutions. Introduction.
doi:10.1051/rnd:19770609 fatcat:4bvyzs5kfrh2ndiv5bl2wne45u