Epitope mapping of anti-human transferrin monoclonal antibodies: potential uses for transferrin-transferrin receptor interaction studies.
ABSTRACT Human transferrin (hTf) is an 80 kDa glycoprotein involved in iron transport from the absorption sites to the sites of storage and utilization. Additionally, transferrin also plays a relevant role as a bacteriostatic agent preventing uncontrolled bacterial growth in the host. In this work we describe a well-characterized Mabs panel in terms of precise epitope localization and estimate affinity for the two major hTf isoforms. We found at least four antigenic regions in the hTf molecule, narrowed down the interacting antigen residues within three of such regions, and located them on a molecular model of hTf. Two of the antigenic regions partially overlap with previously described transferrin-binding sites for both human receptor (antigenic region I: containing amino acid residues from Asp-69 to Asn-76 at the N-lobe) and bacterial receptors from two pathogenic species (antigenic region III: amino acid residues from Leu-665 to Ser-672 at the C-lobe). Hence, such monoclonal antibodies (Mabs) could be used as an additional tool for conformational studies and/or the characterization of the interaction between hTf and both types of receptor molecules.
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ABSTRACT: Edited by Paul Carter Two LipL32-specific mouse monoclonal antibodies (mAbLPF1 and mAbLPF2) which neutralized Leptospira-mediated hemolysis in vitro and rescued hamsters from lethal Leptospira infection were produced. In this communica-tion, locations and characteristics of the protective epitopes of the mAbs were studied by using a truncated LipL32 recombinant protein based-immunoassay and phage con-sensus mimotope identification and multiple alignments. The mAbLPF1 epitope consisted of P243, L244, I245, H246, L252 and Q253 on the LipL32 protein; it is mapped on the surface-exposed region of non-continuous b13-turn and C-terminal amphipathic a6 helix with hydrophobic patch, contributing to phospholipid/host cell adhesion and membrane insertion on one side, and hydrophilic, acidic and basic amino acid residues on another side. The epitope peptide of the mAbLPF2 is linear 122PEEKSMPHW130 and located on surface-exposed a1 and a2 between b7 and b8 that bound to several host constituents. Both epitopes are highly conserved among the pathogenic and inter-mediately pathogenic Leptospira spp. and are absent from the LipL32 superfamily proteins of other microorganisms. This study not only enlightens the molecular mechanisms of the therapeutic mAbLPF1 and mAbLPF2, but also ela-borates the potential of the two LipL32 regions as diagnos-tic and vaccine targets for leptospirosis. Keywords: epitope mapping/Leptospira adhesive matrices/ leptospirosis/mimotopes/neutralizing mAb IntroductionProtein Engineering Design and Selection 04/2014; 27(5):135-144. · 2.32 Impact Factor
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ABSTRACT: Optical biosensor technology continues to be the method of choice for label-free, real-time interaction analysis. But when it comes to improving the quality of the biosensor literature, education should be fundamental. Of the 1413 articles published in 2008, less than 30% would pass the requirements for high-school chemistry. To teach by example, we spotlight 10 papers that illustrate how to implement the technology properly. Then we grade every paper published in 2008 on a scale from A to F and outline what features make a biosensor article fabulous, middling or abysmal. To help improve the quality of published data, we focus on a few experimental, analysis and presentation mistakes that are alarmingly common. With the literature as a guide, we want to ensure that no user is left behind.Journal of Molecular Recognition 12/2009; 23(1):1-64. · 3.01 Impact Factor