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Ramirez-Franco J, Azzaz F, Sangiardi M, Ferracci G, Youssouf F, Popoff MR, Seagar M, Lévêque C, Fantini J, El Far O. Molecular landscape of BoNT/B bound to a membrane-inserted synaptotagmin/ganglioside complex. Cell Mol Life Sci 2022; 79:496. [PMID: 36006520 PMCID: PMC11073447 DOI: 10.1007/s00018-022-04527-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 08/10/2022] [Accepted: 08/11/2022] [Indexed: 11/03/2022]
Abstract
Botulinum neurotoxin serotype B (BoNT/B) uses two separate protein and polysialoglycolipid-binding pockets to interact with synaptotagmin 1/2 and gangliosides. However, an integrated model of BoNT/B bound to its neuronal receptors in a native membrane topology is still lacking. Using a panel of in silico and experimental approaches, we present here a new model for BoNT/B binding to neuronal membranes, in which the toxin binds to a preassembled synaptotagmin-ganglioside GT1b complex and a free ganglioside allowing a lipid-binding loop of BoNT/B to interact with the glycone part of the synaptotagmin-associated GT1b. Furthermore, our data provide molecular support for the decrease in BoNT/B sensitivity in Felidae that harbor the natural variant synaptotagmin2-N59Q. These results reveal multiple interactions of BoNT/B with gangliosides and support a novel paradigm in which a toxin recognizes a protein/ganglioside complex.
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Affiliation(s)
- Jorge Ramirez-Franco
- 1INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015, Marseille, France
| | - Fodil Azzaz
- 1INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015, Marseille, France
| | - Marion Sangiardi
- 1INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015, Marseille, France
| | - Géraldine Ferracci
- Aix-Marseille Université (AMU), CNRS, INP, Institute of Neurophysiopathology, UMR7051, PINT, PFNT, Marseille, France
| | - Fahamoe Youssouf
- 1INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015, Marseille, France
| | | | - Michael Seagar
- 1INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015, Marseille, France
| | - Christian Lévêque
- 1INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015, Marseille, France.
| | - Jacques Fantini
- 1INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015, Marseille, France
| | - Oussama El Far
- 1INSERM, Aix-Marseille Université (AMU), UMR 1072, Unité de Neurobiologie des canaux Ioniques et de la Synapse, 13015, Marseille, France.
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Azzaz F, Yahi N, Di Scala C, Chahinian H, Fantini J. Ganglioside binding domains in proteins: Physiological and pathological mechanisms. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2022; 128:289-324. [PMID: 35034721 DOI: 10.1016/bs.apcsb.2021.08.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Gangliosides are anionic lipids that form condensed membrane clusters (lipid rafts) and exert major regulatory functions on a wide range of proteins. In this review, we propose a new view of the structural features of gangliosides with special emphasis on emerging properties associated with protein binding modes. We analyze the different possibilities of molecular associations of gangliosides in lipid rafts and the role of cholesterol in this organization. We are particularly interested in amide groups of N-acetylated sugars which make it possible to neutralize the negative charge of the carboxylate group of sialic acids. We refer to this effect as "NH trick" and we demonstrate that it is operative in GM1, GD1a, GD1b and GT1b gangliosides. The NH trick is key to understand the different topologies adopted by gangliosides (chalice-like at the edge of lipid rafts, condensed clusters in central areas) and their impact on protein binding. We define three major types of ganglioside-binding domains (GBDs): α-helical, loop shaped, and large flat surface. We describe the mode of interaction of each GBD with typical reference proteins: synaptotagmin, 5HT1A receptor, cholera and botulinum toxins, HIV-1 surface envelope glycoprotein gp120, SARS-CoV-2 spike protein, cellular prion protein, Alzheimer's β-amyloid peptide and Parkinson's disease associated α-synuclein. We discuss the common mechanisms and peculiarities of protein binding to gangliosides in the light of physiological and pathological conditions. We anticipate that innovative ganglioside-based therapies will soon show an exponential growth for the treatment of cancer, microbial infections, and neurodegenerative diseases.
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Affiliation(s)
- Fodil Azzaz
- INSERM UMR_S 1072, Marseille, France; Aix-Marseille Université, Marseille, France
| | - Nouara Yahi
- INSERM UMR_S 1072, Marseille, France; Aix-Marseille Université, Marseille, France
| | - Coralie Di Scala
- Neuroscience Center-HiLIFE, University of Helsinki, Helsinki, Finland
| | - Henri Chahinian
- INSERM UMR_S 1072, Marseille, France; Aix-Marseille Université, Marseille, France
| | - Jacques Fantini
- INSERM UMR_S 1072, Marseille, France; Aix-Marseille Université, Marseille, France.
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Takeuchi T, Okuno T, Miyashiro A, Kohda T, Miyamoto R, Izumi Y, Kozaki S, Kaji R. Clinical Safety and Tolerability of A2NTX, a Novel Low-Molecular-Weight Neurotoxin Derived from Botulinum Neurotoxin Subtype A2, in Comparison with Subtype A1 Toxins. Toxins (Basel) 2021; 13:824. [PMID: 34822610 PMCID: PMC8623066 DOI: 10.3390/toxins13110824] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/11/2021] [Accepted: 11/16/2021] [Indexed: 11/29/2022] Open
Abstract
All the botulinum type A neurotoxins available for clinical use are of the A1 subtype. We developed a subtype A2 low-molecular-weight (150 kD (kilo Dalton)) neurotoxin (A2NTX) with less spread and faster entry into the motor nerve terminal than A1 in vitro and in vivo. Preliminary clinical studies showed that its efficacy is superior to A1 toxins. We conducted an open study exploring its safety and tolerability profile in comparison with A1LL (LL type A1 toxin, or onabotulinumtoxinA) and a low-molecular-weight (150 kD) A1 neurotoxin (A1NTX). Those who had been using A1LL (n = 90; 50-360 mouse LD50 units) or A1NTX (n = 30; 50-580 units) were switched to A2NTX (n = 120; 25-600 units) from 2010 to 2018 (number of sessions ~27, cumulative doses ~11,640 units per patient). The adverse events for A2NTX included weakness (n = 1, ascribed to alcoholic polyneuropathy), dysphagia (1), local weakness (4), and spread to other muscles (1), whereas those for A1LL or A1NTX comprised weakness (n = 2, A1NTX), dysphagia (8), ptosis (6), local weakness (7), and spread to other muscles (15). After injections, 89 out of 120 patients preferred A2NTX to A1 for the successive sessions. The present study demonstrated that A2NTX had clinical safety up to the dose of 500 units and was well tolerated compared to A1 toxins.
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Affiliation(s)
- Toshiaki Takeuchi
- Department of Clinical Neuroscience, Graduate School of Medicine, Tokushima University, Tokushima 770-8503, Japan; (T.T.); (T.O.); (A.M.); (R.M.); (Y.I.)
| | - Tsuyoshi Okuno
- Department of Clinical Neuroscience, Graduate School of Medicine, Tokushima University, Tokushima 770-8503, Japan; (T.T.); (T.O.); (A.M.); (R.M.); (Y.I.)
| | - Ai Miyashiro
- Department of Clinical Neuroscience, Graduate School of Medicine, Tokushima University, Tokushima 770-8503, Japan; (T.T.); (T.O.); (A.M.); (R.M.); (Y.I.)
| | - Tomoko Kohda
- Department of Veterinary Sciences, School of Life and Environmental Sciences, Osaka Prefecture University, Osaka 598-8531, Japan; (T.K.); (S.K.)
| | - Ryosuke Miyamoto
- Department of Clinical Neuroscience, Graduate School of Medicine, Tokushima University, Tokushima 770-8503, Japan; (T.T.); (T.O.); (A.M.); (R.M.); (Y.I.)
| | - Yuishin Izumi
- Department of Clinical Neuroscience, Graduate School of Medicine, Tokushima University, Tokushima 770-8503, Japan; (T.T.); (T.O.); (A.M.); (R.M.); (Y.I.)
| | - Shunji Kozaki
- Department of Veterinary Sciences, School of Life and Environmental Sciences, Osaka Prefecture University, Osaka 598-8531, Japan; (T.K.); (S.K.)
| | - Ryuji Kaji
- Department of Clinical Neuroscience, Graduate School of Medicine, Tokushima University, Tokushima 770-8503, Japan; (T.T.); (T.O.); (A.M.); (R.M.); (Y.I.)
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Mechanism of Ganglioside Receptor Recognition by Botulinum Neurotoxin Serotype E. Int J Mol Sci 2021; 22:ijms22158315. [PMID: 34361086 PMCID: PMC8346984 DOI: 10.3390/ijms22158315] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 01/10/2023] Open
Abstract
The botulinum neurotoxins are potent molecules that are not only responsible for the lethal paralytic disease botulism, but have also been harnessed for therapeutic uses in the treatment of an increasing number of chronic neurological and neuromuscular disorders, in addition to cosmetic applications. The toxins act at the cholinergic nerve terminals thanks to an efficient and specific mechanism of cell recognition which is based on a dual receptor system that involves gangliosides and protein receptors. Binding to surface-anchored gangliosides is the first essential step in this process. Here, we determined the X-ray crystal structure of the binding domain of BoNT/E, a toxin of clinical interest, in complex with its GD1a oligosaccharide receptor. Beyond confirmation of the conserved ganglioside binding site, we identified key interacting residues that are unique to BoNT/E and a significant rearrangement of loop 1228–1237 upon carbohydrate binding. These observations were also supported by thermodynamic measurements of the binding reaction and assessment of ganglioside selectivity by immobilised-receptor binding assays. These results provide a structural basis to understand the specificity of BoNT/E for complex gangliosides.
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