title: Detection of intermolecular transferred NOEs in large protein complexes using asymmetric deuteration: HIV-1 gp120 in complex with a CCR5 peptide.
abstract: Weak protein-protein and protein-ligand interactions play important roles in biological recognition. In many cases, simplification of structural studies of large protein complexes is achieved by investigation of the interaction between the protein and a weakly binding segment of its protein ligand. Detection of pairwise interactions in such complexes is a major challenge for both X-ray crystallography and nuclear magnetic resonance. We demonstrate that transferred nuclear Overhauser effect (TRNOE), in combination with asymmetric deuteration of a protein and a peptide ligand can be used to detect intermolecular interactions in large protein complexes with molecular weights up to ~ 100 kDa. Using this approach, we revealed interactions between tyrosine residues of a 27-residue peptide (deuterated at Ile and Val residues) corresponding to the N-terminal segment of the human C-C chemokine receptor 5 (CCR5) chemokine receptor, and a 43 kDa construct of gp120 envelope protein of human immunodeficiency virus type 1 (deuterated on all aromatics) complexed with a cluster of differentiation 4-mimic miniprotein. The complex was present mostly as a dimer as determined by T2 relaxation measurements. The TRNOE crosspeaks in the ternary complex were assigned to the specific Tyr protons in the CCR5 peptide and to methyl protons, predominantly of isoleucine residues, and also of leucine and/or valine residues of gp120. The TRNOE/asymmetric deuteration method benefits from the sensitivity of the homonuclear NOESY experiment and does not suffer the sensitivity losses associated with isotope-edited/isotope-filtered approaches that rely on magnetization transfer between protons and heteronuclei that are bonded to them. The technique can be widely applied for studying large protein complexes that exhibit fast off-rates.
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Gautam
authors.initials: G
authors.lastname: Srivastava
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Adi
authors.initials: A
authors.lastname: Moseri
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Naama
authors.initials: N
authors.lastname: Kessler
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Sabine R
authors.initials: SR
authors.lastname: Akabayov
authors.affiliation: Department of Chemistry and Macromolecular Assembly Institute, College of Staten Island of the City University of New York, Staten Island, NY, USA.|The Graduate Center of the City University of New York, NY, USA.
authors.forename: Boris
authors.initials: B
authors.lastname: Arshava
authors.affiliation: Department of Chemistry and Macromolecular Assembly Institute, College of Staten Island of the City University of New York, Staten Island, NY, USA.|The Graduate Center of the City University of New York, NY, USA.
authors.forename: Fred
authors.initials: F
authors.lastname: Naider
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Jacob
authors.initials: J
authors.lastname: Anglister
mesh_terms: D001665:Binding Sites; D018360:Crystallography, X-Ray; D003903:Deuterium; D015699:HIV Envelope Protein gp120 / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D007532:Isoleucine / Q000737:chemistry / Q000378:metabolism; D007930:Leucine / Q000737:chemistry / Q000378:metabolism; D046912:Multiprotein Complexes / Q000737:chemistry / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D011522:Protons; D019713:Receptors, CCR5 / Q000737:chemistry* / Q000378:metabolism; D014443:Tyrosine / Q000737:chemistry / Q000378:metabolism; D014633:Valine / Q000737:chemistry / Q000378:metabolism
chemical_list: D015699:HIV Envelope Protein gp120; D046912:Multiprotein Complexes; D010455:Peptides; D011522:Protons; D019713:Receptors, CCR5; D007532:Isoleucine; D014443:Tyrosine; D003903:Deuterium; D007930:Leucine; D014633:Valine
keywords: gp120; human C-C chemokine receptor 5; human immunodeficiency virus type 1; intermolecular interactions; nuclear magnetic resonance; transferred nuclear Overhauser effect