Signal sequence cleaved between Lys40 and Ser41 (Uniprot numbering). The protein is post-translationally N- and O- glycosylated. C-terminus modified with 6xHisTag connected by 17aa long linker. he protein construct used for SAXS contains an additional polyhistidine 6x HisTag at the C-terminus for affinity purification connected to a non-native 17 amino acid linker (HLEQKLISEEDLNSAVDHHHHHH).