Lactotransferrin human serotransferrin

Leger, D., Verbert, A., Loucheux, M.-H. and Spik, G. 1977. Study of the molecular weight of human lactotransferrin and serotransferrin. Ann. Biol. Anim. Biochim. Biophys. 17, 737-747 (French). 

Carbohydrates of human serotransferrin are not fucosylated, while those of human lactotransferrin have an a-l,6-fucose bound to the N-acetylglucosamine residue linked to the peptide chain, and an a-l,3-fucose bound to the N-acetyllactosamine residues. 

Two structures [(53) and (54)1 are proposed for the unique glycan of hen egg-white ovotransferrin. A comparative study of this glycan with those of human serotransferrin and lactotransferrin reveals profound differences that could form the basis for the specificity of recognition of target cells by these glycoproteins. 

Structural comparison of the iron binding sites of N-lobe of rabbit serotransferrin, human lactotransferrin and... 

Serotransferrin glycans are generally non-fucosylated except in human cerebrospinal fluid (trace amounts) [246,247], rat (20-30% of the molecules) [221], pig (100% of the molecules) [220] and the serotransferrin-like glycoprotein from mouse milk [218,219] in which this protein co-exists with a lactotransferrin. None of the serotransferrin glycans... 

As mentioned above (see section 2.2.1), the three-dimensional structure of the peptide chains of rabbit serotransferrin, of human and bovine lactotransferrins and of ovotrans-... 

As mentioned above. X-ray diffraction of transferrin furnishes little information on the 3D-structure of the glycans and the images we have today remain largely speculative since they result from molecular modelling studies. We have represented in Fig. 21 the 3D-structure, determined by molecular modelling on the basis of X-ray diffraction data of rabbit serotransferrin [276] and of human lactotransferrin [89,92]. In rabbit serotransferrin, the single glycan linked to the peptide chain is immobilized into only... 

Fig. 21. Molecular modelling (A,B) of rabbit serotransferrin glycan and (C) of human lactotransferrin [192, 210,275] (A) 3D structure of rabbit serotransferrin (B) interaction of rabbit serotransferrin glycan in a broken-wing conformation with a peptide segment (amino acids 254 to 271) in an a-helix conformation, 7,7, Al-acetylneuraminic acid residues (see Fig. 6A). (C) 3D structure of human lactotransferrin. Arrows indicate the position of glycans.

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