CFH/FHL-1 BMS202 selleck chemical binding proteins were identified using NHS and a polyclonal anti-CFH antibody. Equal sample loading was assessed by detection of flagellin (FlaB) using MAb L41 1C11 1C11 at a dilution of 1:1000. Mobilities of molecular mass standards are indicated to the left. Four proteins able to bind CFH/FHL-1 and they are readily digested by proteinases and therefore located on the membrane. Cloning and identification of the CFH/FHL-1 binding proteins of B. garinii ST4 PBi Assuming that the genes encoding CFH/FHL-1 binding proteins of B. garinii ST4 PBi share similarity to CspA encoding cspA gene of B. burgdorferi ss B31, B. afzelii MMS and B. garinii ZQ1, a database search was conducted. Four genes revealed a high degree of similarity

with either CspA of B. burgdorferi ss B31, B. afzelii MMS or B. garinii ZQ1 as described previously [31, 34]. BGA66, find more BGA67, BGA68 and BGA71 showed similarity to previously described CspA of about 50%. Comparative

sequence analysis, revealed that orthologs BGA66 and BGA71 were found to have the highest degree of similarity within the putative CFH/FHL-1 binding regions of CspA (region 1-3)[35–37]. BGA66, BGA67, BGA68 and BGA 71 as well as CspA of B. burgdorferi ss strain B31 were cloned and expressed as GST fusion proteins. Determination of binding of CspA orthologs to CFH and FHL-1 Binding of CFH and FHL-1 to non-denatured purified recombinant proteins was evaluated by ligand affinity blot. Proteins were separated under denaturing conditions and subsequently blotted on a nitrocellulose membrane. As shown in Fig 5, BbCspA used as positive control bound strongly to CFH and FHL-1 as described previously [34]. Orthologs BGA66 and BGA71 were capable of binding to both complement regulators, however, with reduced intensities compared to CspA. Figure 5 Binding capabilities of CFH and

FHL-1 to CspA orthologs of B. garinii ST4. Purified GST fusion proteins, BbCspA, BGA66, BGA67, BGA69, and BGA71 (500 ng/lane) were subjected to 10% Tris/Tricine SDS-PAGE and blotted to nitrocellulose membranes. Membranes were then incubated with recombinant FHL-1 or with NHS. GST-fusion proteins were detected by using anti-goat GST antibody and binding to CFH and FHL-1 were visualized using mAb VIG8 PTK6 specific for the C-terminal region of CFH and αSCR1-4 antiserum specific for the N-terminal region of FHL-1. Binding of CFH and FHL-1 is visible for BGA66 and BGA71. To further confirm binding of CspA orthologs an ELISA was conducted. CspA orthologs BGA66, BGA67, BGA68, and BGA71 were immobilized on a microtiter plate and binding of CFH and FHL-1 was evaluated (Fig 6). BbCRASP-1 used as a positive control strongly bound to CFH and FHL-1. Of the four CspA orthologs analyzed, BGA66 was capable of binding to both complement regulators, this binding was significantly higher than the baseline (p < 0.05). Ortholog BGA71 specifically bound to FHL-1 (p < 0.05) but less efficiently than CspA and BGA66.