SUPPLEMENTARY FIGURE 1: Schematic representation of recombinant LILRA3 proteins produced from 293T mammalian cells, E. coli and P. pastoris. LILRA3 was cloned from the mature functional domain and expressed with additional tags as illustrated.

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SUPPLEMENTARY FIGURE 2: Amino acid sequence of full length LILRA3. The five predicted glycosylation sites as per NetNGlyc 1.0 analysis software are at asparagine (N) N140, N281, N302, N341 and N431. Those N shown in red are predicted with a threshold of 0.5 while N shown in blue is predicted with a threshold of 0.25.

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SUPPLEMENTARY FIGURE 3. Tandem mass spectrometry confirming PNGase F treatment of recombinant LILRA3 does not result in spontaneous deamidation. PNGase F deglycosylated rLILRA3 from E. coli were in gel digested by trypsin and deamidation of asparagine to aspartic acid indicating N-linked glycosylation was determined by Nano LC-MS/MS. Representative mass spectrum confirming no deamidation of N-linked glycosylation site at N140 (A), N281 (B), N302 (C), N341(D) and N431 (E). The sequence of the peptide, the fragmentation pattern and the detected fragment ions are shown top-right of each panel. b ions contain the N-terminal region of the peptide, y ions contain the C-terminal region of the peptide. Non-deamidated asparagine remains designated as “N” without an underscore.

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