Siglec-10 interacts with VAP-1. (A) The amino acid sequence obtained from randomly picked clones after 4 rounds of selection and its match to Siglec-10 and the binding of the corresponding synthetic peptide to recombinant VAP-1 (100 ng/well) in ELISA. The results are mean ± SEM from 3 separate experiments and triplicate wells in each experiment. (B) Binding of recombinant VAP-1 to Siglec-10–Ig chimera. Siglec-10–Ig chimera was immobilized onto ELISA microtiter wells via an anti-hIgG antibody. hIg was used as a negative control. The results are presented as relative binding ratios and are mean ± SEM from 3 separate experiments, each having triplicate wells. (C) Binding of recombinant VAP-1 to CHO cells expressing Siglec-10 and to mock-transfected control cells as detected by anti–VAP-1 antibody. Negative controls are incubations with antibodies without the addition of recombinant VAP-1. The results are mean ± SEM of mean fluorescence intensities measured by flow cytometer from 2 separate experiments. (D) Binding of CFSE-labeled Siglec-10 transfectants to CHO cells expressing VAP-1 and mock controls. The results are mean ± SEM of fluorescent intensities measured by fluorometer from 7 separate experiments, each having duplicate wells. (E) The contribution of sialic acids to the interaction was tested by treating either the cells expressing VAP-1 and or the cells expressing Siglec-10 with neuraminidase to remove the sialic acids. The results are means of fluorescent intensities ± SEM from 4 separate experiments, each having duplicate wells. *P < .05. **P < .01. ***P < .001.