Mannose-binding lectin (PubMed:9892687). Accommodates most effectively a non-reducing terminal alpha-d-mannosyl unit. Strongly precipitates murine IgM but not IgG (PubMed:9949194). Dimer (alpha/beta)2 (PubMed:9949194). Tetramer (alpha/beta)4 (PubMed:10843844). Glycosylated at Asn-125 by either a paucimannose type N-glycan (alpha-4) or a single N-acetylglucosamine (alpha-3). Glycosylated at Asn-131 by a paucimannose type N-glycan (alpha-2, alpha-3 and alpha-4). In alpha-2, Asn-125 is deamidated to an Asp, possibly due to the action of intrinsic peptide N-glycosidase (PGNase). Preserves hematopoietic progenitors in suspension culture by preventing their proliferation and differentiation even in the presence of a cytokine known for its strong induction of proliferation and differentiation (PubMed:9892687). FRIL's ability to preserve quiescent primitive cells in a reversible manner may significantly expand the time and range of ex vivo manipulations of human stem cells for clinical applications (PubMed:10880759). Four different alpha subunits (alpha-1, alpha-2, alpha-3 and alpha-4) are observed and their different polypeptide masses might be due to differential C-terminal processing of the corresponding polypeptide or to differential N-glycosylation of subunits. Alpha-1 lacks the 8 amino acids N-terminal sequence present in the other alpha subunits. Alpha-2 and Alpha-4 differ in their glycosylation pattern. Alpha-3 et Alpha-4 are N-glycosylated at their N-terminus. The Asn N-terminus of alpha-2 is deamidated into Asp. Belongs to the leguminous lectin family. The amino acid substitutions in both the subunits found in PubMed:24907509 might have resulted from different cultivars or growing conditions of the plant used in the study.