Three-dimensional structure of mare diferric lactoferrin at 2.6 Å resolution

Structural and Functional Characterization of Ovotransferrin Produced byPichia pastoris

“…1) They are $80 kDa single-chain bilobal proteins with one Fe 3þ -binding site in each lobe. X-ray crystallographic data for the diferric forms of lactoferrin, 2) serum transferrin, 3) and ovotransferrin 4,5) have demonstrated that the N and C-lobes have similar tertiary structures. Each lobe is made up of a pair of domains (domain 1 and domain 2) and a single high affinity Fe 3þ -binding site is located in the interdomain cleft.…”

Lactoferrin–metal interactions: first crystal structure of a complex of lactoferrin with a lanthanide ion (Sm3+) at 3.4 Å resolution

“…The crystals of disamarium lactoferrin were isomorphous with native diferric lactoferrin crystals (Sharma, Paramasivam et al, 1999). The re®ned atomic coordinates of the diferric lactoferrin structure were used as the starting model for re®nement, after removing Fe 3+ and CO 2À 3 ions, the solvent molecules, protein side chains involved in metal binding (four in each binding site) and anion-binding protein side chains (Arg121 and Arg463, Thr117 and Thr459).…”

“…These proteins fold into two lobes which are connected by a 10±12 residue long peptide. (Ainscough et al, 1979), VO 2+ (Chasteen et al, 1977), VO 2 (Harris & Carrano, 1984), lanthanide cations (Luk, 1971;Zak & Aisen, 1988;O'Hara & Bersohn, 1982) and Th 4+ (Harris et al, 1981) Crystallographic analysis of rabbit serum transferrin (Bailey et al, 1988), diferric human lactoferrin (Anderson et al, 1989;Haridas et al, 1995), hen ovotransferrin (Kurokawa et al, 1995), duck ovotransferrin (Rawas et al, 1996), bovine lactoferrin (Moore et al, 1997), mare lactoferrin (Sharma, Paramasivam et al, 1999) and buffalo lactoferrin (Karthikeyan et al, 1999a,b) have de®ned the location and nature of the iron sites. All these proteins have essentially the same bilobal structure, with one iron site in each lobe, deep in a cleft between two domains.…”

Anion-mediated Fe3+ Release Mechanism in Ovotransferrin C-lobe

“…The two iron-binding sites are located within the interdomain cleft of each lobe. From the crystal structures of the diferric forms (15)(16)(17)(18)(19)(20) and the monoferric N-lobes (21)(22)(23)(24) of several transferrins, it has been shown that the two domains of each lobe are closed over an Fe 3ϩ ion. Out of the six coordination sites of Fe 3ϩ , four are occupied by protein ligands (two Tyr, one Asp, and one His residues), and the other two are occupied by a bidentate carbonate anion.…”