Insights from NMR Spectroscopy into the Conformational Properties of Man-9 and Its Recognition by Two HIV Binding Proteins.
Man9GlcNAc2(Man-9) present at the surface of HIV makes up the binding sites of several HIV-neutralizing agents and the mammalian lectin DC-SIGN, which is involved in cellular immunity and trans-infections. We describe the conformational properties of Man-9 in its free state and when bound by the HIV entry-inhibitor protein microvirin (MVN), and define the minimum epitopes of both MVN and DC-SIGN by using NMR spectroscopy. To facilitate the implementation of 3D13C-edited spectra to deconvolute spectral overlap and to determine the solution structure of Man-9, we developed a robust expression system for the production of13C,15N-labeled glycans in mammalian cells. The studies reveal that Man-9 interacts with HIV-binding proteins through distinct epitopes and adopts diverse conformations in the bound state. In combination with molecular dynamics simulations we observed receptor-bound conformations to be sampled by Man-9 in the free state, thus suggesting a conformational selection mechanism for diverse recognition.
Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, 8 Center Drive, Bethesda, MD, 20892, USA.|Structural Biology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, 40 Convent Drive, Bethesda, MD, 20892, USA.|Present address: Department of Biology, SBA School of Science and Engineering, Lahore University of Management Sciences, Lahore, 54792, Pakistan.
Syed
S
Shahzad-Ul-Hussan
Structural Biology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, 40 Convent Drive, Bethesda, MD, 20892, USA.
Mallika
M
Sastry
Structural Biology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, 40 Convent Drive, Bethesda, MD, 20892, USA.|Structural Bioinformatics Core Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, 40 Convent Drive, Bethesda, MD, 20892, USA.
Thomas
T
Lemmin
Structural Biology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, 40 Convent Drive, Bethesda, MD, 20892, USA.|Structural Bioinformatics Core Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, 40 Convent Drive, Bethesda, MD, 20892, USA.
Cinque
C
Soto
Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, 8 Center Drive, Bethesda, MD, 20892, USA.
Sandra
S
Loesgen
Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, 8 Center Drive, Bethesda, MD, 20892, USA.
Danielle A
DA
Scott
Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, 8 Center Drive, Bethesda, MD, 20892, USA.
Jack R
JR
Davison
Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, 8 Center Drive, Bethesda, MD, 20892, USA.
Katheryn
K
Lohith
Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, 8 Center Drive, Bethesda, MD, 20892, USA.
Robert
R
O'Connor
Structural Biology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, 40 Convent Drive, Bethesda, MD, 20892, USA.|Structural Bioinformatics Core Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, 40 Convent Drive, Bethesda, MD, 20892, USA.
Peter D
PD
Kwong
Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, 8 Center Drive, Bethesda, MD, 20892, USA.
Carole A
0000-0003-2203-0852
CA
Bewley
D000072283:A549 Cells; D001426:Bacterial Proteins / Q000737:chemistry*; D002236:Carbohydrate Conformation; D002250:Carbon Radioisotopes; D015815:Cell Adhesion Molecules / Q000737:chemistry*; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000378:metabolism; D015497:HIV-1 / Q000378:metabolism; D006801:Humans; D037181:Lectins, C-Type / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008351:Mannans / Q000096:biosynthesis / Q000737:chemistry*; D037601:Mannose-Binding Lectin / Q000737:chemistry*; D046931:Microcystis; D056004:Molecular Dynamics Simulation; D009590:Nitrogen Radioisotopes; D011956:Receptors, Cell Surface / Q000737:chemistry*; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin
D001426:Bacterial Proteins; D002250:Carbon Radioisotopes; D015815:Cell Adhesion Molecules; D015699:HIV Envelope Protein gp120; D037181:Lectins, C-Type; D008351:Mannans; D037601:Mannose-Binding Lectin; D009590:Nitrogen Radioisotopes; D011956:Receptors, Cell Surface; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin; C475461:mannosyl(9)-N-acetylglucosamine2; C552210:microvirin protein, Microcystis aeruginosa
NMR spectroscopy; carbohydrate recognition; glycan conformation; isotopic labeling; molecular dynamics