L-ficolin is a pattern recognition molecule specific for acetyl groups.
L-ficolin and H-ficolin are molecules of the innate immune system. Upon recognition of a suitable target they activate the complement system. The ligand recognition structure of ficolins is contained within a fibrinogen-like domain. We examined the selectivity of the ficolins through inhibiting the binding to bacteria or to beads coupled with N-acetylglucosamine. The binding of L-ficolin to Streptococcus pneumoniae 11F and the beads was inhibited by N-acetylated sugars and not by non-acetylated sugars. However, it was also inhibited by other acetylated compounds. Based on this selectivity L-ficolin is not easily defined as a lectin. The binding of H-ficolin to Aerococcus viridans was not inhibited by any of the sugars or other compounds examined. Based on the selectivity of L-ficolin we developed a new purification procedure involving affinity chromatography on N-acetylcysteine-derivatized Sepharose. The column was loaded in the presence of EDTA and high salt, and L-ficolin was eluted by decreasing the salt concentration. Further purification was achieved by ion exchange chromatography.
Krarup
Anders
A
Institute of Medical Microbiology and Immunology, University of Aarhus, 8000 Aarhus, Denmark.
Thiel
Steffen
S
Hansen
Annette
A
Fujita
Teizo
T
Jensenius
Jens C
JC
D000107:Acetylation; D000117:Acetylglucosamine / Q000737:chemistry / Q000378:metabolism*; D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000737:chemistry / Q000378:metabolism; D001798:Blood Proteins / Q000235:genetics / Q000378:metabolism; D002846:Chromatography, Affinity; D003167:Complement Activation; D006801:Humans; D037102:Lectins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D016415:Sequence Alignment; D013289:Streptococcaceae / Q000276:immunology; D013296:Streptococcus pneumoniae / Q000276:immunology; D013379:Substrate Specificity; D000097604:Ficolins
D000117:Acetylglucosamine; D000942:Antigens, Bacterial; D001798:Blood Proteins; D037102:Lectins; D000097604:Ficolins; C121518:TL-5A protein, Tachypleus tridentatus