As explained in the discussion, this site was defined as occurring after a glutamine residue, resulting in a VP1 protein of 211 (O1 Manisa and A24 Cruzeiro) or 209 (Asia 1 Shamir) amino acids. Molecular masses were predicted using the program Lasergene (DNASTAR). Tryptic cleavage fragments were predicted using the web-based tool http://www.expasy.org/tools/peptide-mass.html. Molecular masses of assemblies of tryptic fragments were calculated by adding the masses of the individual fragments and subtracting the mass of a water molecule (18 Da) per addition. We assumed an increase in molecular mass of 210 Da for addition of a myristoyl group to VP4 [15]. The small scale yeast production
of the FMDV binding VHHs M3, M23 selleck kinase inhibitor and M8 encoded by pRL188-derived plasmids and their purification by a single immobilized-metal affinity chromatography step has been described previously [13]. This results in the production of VHHs with a C-terminal extension with amino acid
sequence EPKTPKPQPQPQPQPQPNPTTESKCPHHHHHH. CAL-101 order The control VHH K609 that binds to Escherichia coli fimbriae [16] was produced in a similar manner. A double oil emulsion (DOE) was prepared at laboratory scale by emulsification of 7.5 μg/ml FMDV O1 Manisa antigen in WF1 buffer with oil (90% Marcol 52; 10% Montanide 80) using a mixing device (Ultraturrax; IKA-Werke, Staufen, Germany). The resulting first emulsion was then emulsified with WF1 buffer containing 2% Tween-80, resulting in a water-in-oil-in-water emulsion. To break the emulsion the DOE vaccine was 10-fold Calpain diluted in EBT buffer (0.05% Tween-20; 0.5 M NaCl; 2.7 mM KCl; 2.8 mM KH2PO4; 8.1 mM Na2HPO4; pH 7.4) and vortexed for 20 min at 1700 rpm. After 1 min centrifugation at 14,000 rpm in a micro-centrifuge the
upper oil phase was removed. The resulting extract was used for subsequent SELDI-TOF-MS analysis of FMDV antigen. A sample of FMDV antigen before the first emulsification was similarly extracted. Normal-phase (NP20) ProteinChip arrays (BioRad, Hercules, CA) were wetted by applying 1 μl water per spot and subsequently 1 μl of FMDV sample containing 0.15 mg/ml 146S. The array was then allowed to air dry, washed using 5 μl water per spot and dried again. 1 μl saturated sinapinic acid (in 50% acetonitrile, 0.5% trifluoroacetic acid) was added to each spot twice. The spots were air dried after each addition. Covalent coupling of VHHs to RS100 ProteinChip arrays (BioRad) was performed overnight by addition of 1 μg VHH in 4 μl PBS to each spot. Subsequent incubations were performed using the array BioProcessor (BioRad). Residual amine-reactive groups were blocked by incubation with 0.5 M Tris·Cl pH 8.0. The arrays were then incubated for 2 h with FMDV antigens at a concentration of 10 μg/ml 146S in PBS containing 0.5% Triton-X 100 and subsequently washed three times using PBS containing 0.5% Triton-X 100 and two times using PBS. After a brief rinse in 5 mM Hepes pH 8.