Application of the disulfide trapping approach to explain the antiparallel assembly of dimeric rabbit uteroglobin: A preliminary study using short peptide models

The spontaneous air oxidation of the peptides H-GICPRFAHVIENLL- NH2 and Ac-LPQTTRENIMKLTEKIVKSPLCM-OH, whose sequences correspond to the helicoidal fragments 1–14 and 48–70 of the monomer of rabbit uteroglobin, was studied. While no oxidation products were observed in the absence of trifluoroethanol, the heterodimer was formed selectively in the presence of the structuring agent. Head-to-head and tail-to-tail homodimers were not detected under these conditions. These results suggest that the N- and C- terminal extremes of the monomer of uteroglobin might contain enough structural information to govern dimerization with a head-tail topology, through a selective helix-to-helix recognition process.