Engineering a therapeutic lectin by uncoupling mitogenicity from antiviral activity.
A key effector route of the Sugar Code involves lectins that exert crucial regulatory controls by targeting distinct cellular glycans. We demonstrate that a single amino-acid substitution in a banana lectin, replacing histidine 84 with a threonine, significantly reduces its mitogenicity, while preserving its broad-spectrum antiviral potency. X-ray crystallography, NMR spectroscopy, and glycocluster assays reveal that loss of mitogenicity is strongly correlated with loss of pi-pi stacking between aromatic amino acids H84 and Y83, which removes a wall separating two carbohydrate binding sites, thus diminishing multivalent interactions. On the other hand, monovalent interactions and antiviral activity are preserved by retaining other wild-type conformational features and possibly through unique contacts involving the T84 side chain. Through such fine-tuning, target selection and downstream effects of a lectin can be modulated so as to knock down one activity, while preserving another, thus providing tools for therapeutics and for understanding the Sugar Code.
Division of Infectious Diseases, Department of Internal Medicine, Program in Immunology, University of Michigan, Ann Arbor, MI 48109, USA; Division of Infectious Diseases, Department of Medicine and UNC AIDS Center, University of North Carolina, Chapel Hill, NC 27599, USA.
Michael D
MD
Swanson
Division of Infectious Diseases, Department of Internal Medicine, Program in Immunology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA.
Daniel M
DM
Boudreaux
Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA.
Loïc
L
Salmon
Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA.
Jeetender
J
Chugh
Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
Harry C
HC
Winter
Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA.
Jennifer L
JL
Meagher
Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, 80539 Munich, Germany.
Sabine
S
André
School of Chemistry, National University of Ireland, Galway, Ireland.
Paul V
PV
Murphy
Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
Stefan
S
Oscarson
Department of Chemistry, Université du Québec à Montréal, Montréal, Québec H3C 3P8, Canada.
René
R
Roy
Division of Infectious Diseases, Department of Internal Medicine, Program in Immunology, University of Michigan, Ann Arbor, MI 48109, USA.
Steven
S
King
Division of Infectious Diseases, Department of Internal Medicine, Program in Immunology, University of Michigan, Ann Arbor, MI 48109, USA.
Mark H
MH
Kaplan
Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
Irwin J
IJ
Goldstein
Institute for Antiviral Research, Utah State University, Logan, UT 84322, USA.
E Bart
EB
Tarbet
Institute for Antiviral Research, Utah State University, Logan, UT 84322, USA.
Brett L
BL
Hurst
Institute for Antiviral Research, Utah State University, Logan, UT 84322, USA.
Donald F
DF
Smee
Rockefeller University, New York, NY 10065, USA.
Cynthia
C
de la Fuente
Rockefeller University, New York, NY 10065, USA.
Hans-Heinrich
HH
Hoffmann
Department of Biochemistry, Duke University, Durham, NC 27710, USA.
Yi
Y
Xue
Rockefeller University, New York, NY 10065, USA.
Charles M
CM
Rice
Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, University of Leuven, 3000 Leuven, Belgium.
Dominique
D
Schols
Division of Infectious Diseases, Department of Medicine and UNC AIDS Center, University of North Carolina, Chapel Hill, NC 27599, USA.
J Victor
JV
Garcia
Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA.
Jeanne A
JA
Stuckey
Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, 80539 Munich, Germany.
Hans-Joachim
HJ
Gabius
Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biochemistry, Duke University, Durham, NC 27710, USA. Electronic address: ha57@duke.edu.
Hashim M
HM
Al-Hashimi
Division of Infectious Diseases, Department of Internal Medicine, Program in Immunology, University of Michigan, Ann Arbor, MI 48109, USA. Electronic address: dmarkov@umich.edu.
David M
DM
Markovitz
D019380:Anti-HIV Agents / Q000737:chemistry; D002240:Carbohydrate Sequence; D005818:Genetic Engineering; D008934:Mitogens / Q000737:chemistry; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D028521:Musa / Q000737:chemistry; D037121:Plant Lectins / Q000737:chemistry* / Q000235:genetics*
D019380:Anti-HIV Agents; D008934:Mitogens; D037121:Plant Lectins