A novel L-ficolin/mannose-binding lectin chimeric molecule with enhanced activity against Ebola virus

Ian C. Michelow, Mingdong Dong, Bruce A. Mungall, L. Michael Yantosca, Calli Lear, Xin Ji, Marshall Karpel, Christina L. Rootes, Matthew Brudner, Gunnar Houen, Damon P. Eisen, T. Bernard Kinane, Kazue Takahashi, Gregory L. Stahl, Gene G. Olinger, Gregory T. Spear, R. Alan B. Ezekowitz, Emmett V. Schmidt

Research output: Contribution to journalArticlepeer-review


Ebola viruses constitute a newly emerging public threat because they cause rapidly fatal hemorrhagic fevers for which no treatment exists, and they can be manipulated as bioweapons. We targeted conserved N-glycosylated carbohydrate ligands on viral envelope surfaces using novel immune therapies. Mannose-binding lectin (MBL) and L-ficolin (L-FCN) were selected because they function as opsonins and activate complement. Given that MBL has a complex quaternary structure unsuitable for large scale cost-effective production, we sought to develop a less complex chimeric fusion protein with similar ligand recognition and enhanced effector functions. We tested recombinant human MBL and three L-FCN/MBL variants that contained the MBL carbohydrate recognition domain and varying lengths of the L-FCN collagenous domain. Non-reduced chimeric proteins formed predominantly nona- and dodecameric oligomers, whereas recombinant human MBL formed octadecameric and larger oligomers. Surface plasmon resonance revealed that L-FCN/MBL76 had the highest binding affinities for N-acetylglucosamine-bovine serum albumin and mannan. The same chimeric protein displayed superior complement C4 cleavage and binding to calreticulin (cC1qR), a putative receptor for MBL. L-FCN/MBL76 reduced infection by wild type Ebola virus Zaire significantly greater than the other molecules. Tapping mode atomic force microscopy revealed that L-FCN/MBL76 was significantly less tall than the other molecules despite similar polypeptide lengths. We propose that alterations in the quaternary structure of L-FCN/MBL76 resulted in greater flexibility in the collagenous or neck region. Similarly, a more pliable molecule might enhance cooperativity between the carbohydrate recognition domains and their cognate ligands, complement activation, and calreticulin binding dynamics. L-FCN/MBL chimeric proteins should be considered as potential novel therapeutics.

Original languageEnglish (US)
Pages (from-to)24729-24739
Number of pages11
JournalJournal of Biological Chemistry
Issue number32
StatePublished - Aug 6 2010
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


Dive into the research topics of 'A novel L-ficolin/mannose-binding lectin chimeric molecule with enhanced activity against Ebola virus'. Together they form a unique fingerprint.

Cite this