title: Synaptotagmin II and gangliosides bind independently with botulinum neurotoxin B but each restrains the other.
abstract: Botulinum neurotoxin type B (BoNT/B) initiates its toxicity by binding to synaptotagmin II (SytII) and gangliosides GD1a and GT1b on the neural membrane. We synthesized two 27-residue peptides that carry the BoNT/B binding sites on mouse SytII (mSytII 37-63) or human SytII (hSytII 34-60). BoNT/B bound to these peptides, but showed substantially higher binding to mSytII peptide than to hSytII peptide. The mSytII peptide inhibited almost completely BoNT/B binding to synaptosomes (snps) and displayed a high affinity. BoNT/B bound strongly to mSytII peptide and binding was inhibited by the peptide. Binding of BoNT/B to snps was also inhibited (~80 %) by a larger excess of gangliosides GD1a or GT1b. The mSytII peptide inhibited very strongly (at least 80 %) the toxin binding to snps, while the two gangliosides were much less efficient inhibitors requiring much larger excess to achieve similar inhibition levels. Furthermore, gangliosides GD1a or GT1b inhibited BoNT/B binding to mSytII peptide at a much larger excess than the inhibition by mSytII peptide. Conversely, BoNT/B bound well to each ganglioside and binding could be inhibited by the correlate ganglioside and much less efficiently by the mSytII peptide. There was no apparent collaboration between mSytII peptide and either ganglioside. mSytII peptide displayed some protective activity in vivo in mice against a lethal BoNT/B dose. We concluded that SytII peptide and gangliosides bind independently but, with their binding sites on BoNT/B being spatially close, each can influence BoNT/B binding to the other due to regional conformational perturbations or steric interference or both. Ganglioside involvement in BoNT/B binding might help in toxin translocation and endocytosis.
authors.affiliation: Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA, matassi@bcm.edu.
authors.forename: M Zouhair
authors.initials: MZ
authors.lastname: Atassi
authors.forename: Midori
authors.initials: M
authors.lastname: Taruishi
authors.forename: Masooma
authors.initials: M
authors.lastname: Naqvi
authors.forename: Lance E
authors.initials: LE
authors.lastname: Steward
authors.forename: K Roger
authors.initials: KR
authors.lastname: Aoki
mesh_terms: D000818:Animals; D001905:Botulinum Toxins / Q000737:chemistry / Q000378:metabolism*; D019274:Botulinum Toxins, Type A; D005732:Gangliosides / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007457:Iodine Radioisotopes / Q000737:chemistry; D051379:Mice; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D050861:Synaptotagmin II / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005732:Gangliosides; D007457:Iodine Radioisotopes; D010455:Peptides; D050861:Synaptotagmin II; C096323:rimabotulinumtoxinB; D001905:Botulinum Toxins; D019274:Botulinum Toxins, Type A
references.citation: J Biol Chem. 2011 Sep 30;286(39):34015-22
references.pmid: 21849494
references.citation: J Biol Chem. 1994 Apr 8;269(14):10498-503
references.pmid: 8144634
references.citation: Biochemistry. 2004 Aug 3;43(30):9725-31
references.pmid: 15274627
references.citation: Microb Pathog. 2007 Feb-Mar;42(2-3):72-9
references.pmid: 17188834
references.citation: FEBS Lett. 1996 Jan 15;378(3):253-7
references.pmid: 8557112
references.citation: J Mol Biol. 2003 Feb 21;326(3):835-47
references.pmid: 12581644
references.citation: Nature. 1962 May 5;194:495-6
references.pmid: 14450081
references.citation: Mol Microbiol. 2004 Feb;51(3):631-43
references.pmid: 14731268
references.citation: Infect Immun. 1997 Jun;65(6):2225-32
references.pmid: 9169755
references.citation: Proc Natl Acad Sci U S A. 1991 May 1;88(9):3613-7
references.pmid: 2023910
references.citation: Philos Trans R Soc Lond B Biol Sci. 1999 Feb 28;354(1381):259-68
references.pmid: 10212474
references.citation: PLoS Pathog. 2008 Aug 15;4(8):e1000129
references.pmid: 18704164
references.citation: J Cell Biol. 1986 Aug;103(2):535-44
references.pmid: 3015983
references.citation: J Infect Dis. 2014 Jan 15;209(2):192-202
references.pmid: 24106295
references.citation: J Infect Dis. 2014 Jan 15;209(2):183-91
references.pmid: 24106296
references.citation: Neurosci Lett. 1996 Apr 19;208(2):105-8
references.pmid: 8859901
references.citation: J Neurochem. 1996 Jun;66(6):2556-61
references.pmid: 8632182
references.citation: Anal Biochem. 1976 May 7;72:248-54
references.pmid: 942051
references.citation: Nature. 2006 Dec 21;444(7122):1092-5
references.pmid: 17167421
references.citation: J Cell Sci. 2012 Jul 1;125(Pt 13):3233-42
references.pmid: 22454523
references.citation: FEBS Lett. 2012 Feb 17;586(4):310-3
references.pmid: 22265973
references.citation: J Cell Biol. 1979 Apr;81(1):43-9
references.pmid: 383721
references.citation: Toxicon. 1982;20(5):841-6
references.pmid: 7179292
references.citation: Nat Commun. 2013;4:2058
references.pmid: 23807078
references.citation: Neuropharmacology. 1974 Aug;13(8):683-91
references.pmid: 4444755
references.citation: J Biochem. 1983 Aug;94(2):521-7
references.pmid: 6630172
references.citation: Nat Struct Biol. 2000 Aug;7(8):693-9
references.pmid: 10932256
references.citation: J Biol Chem. 1987 Feb 25;262(6):2660-3
references.pmid: 3029090
references.citation: J Biol Chem. 2004 Jul 16;279(29):30865-70
references.pmid: 15123599
references.citation: Naunyn Schmiedebergs Arch Pharmacol. 1976 Nov;295(2):171-5
references.pmid: 186722
references.citation: Infect Immun. 1989 Sep;57(9):2634-9
references.pmid: 2668181
references.citation: Biochemistry. 2012 Jan 10;51(1):316-28
references.pmid: 22146011
references.citation: Microb Pathog. 1998 Aug;25(2):91-9
references.pmid: 9712688
references.citation: J Cell Biol. 1977 Oct;75(1):43-55
references.pmid: 914896
references.citation: Biochim Biophys Acta. 2005 Jun 30;1741(1-2):1-3
references.pmid: 15919183
references.citation: J Vet Med Sci. 2000 Nov;62(11):1133-8
references.pmid: 11129854
references.citation: J Cell Biol. 2003 Sep 29;162(7):1293-303
references.pmid: 14504267
references.citation: Toxicon. 2003 Oct;42(5):461-9
references.pmid: 14529727
references.citation: J Neurochem. 1999 May;72(5):1991-8
references.pmid: 10217276
references.citation: Nature. 2006 Dec 21;444(7122):1096-100
references.pmid: 17167418
references.citation: Protein J. 2004 Nov;23(8):539-52
references.pmid: 15648976
references.citation: J Neurosci Res. 1993 Dec 15;36(6):635-45
references.pmid: 8145292
references.citation: Mol Immunol. 2008 Feb;45(4):910-24
references.pmid: 17897717
references.citation: Biochem Biophys Res Commun. 1972 Jul 11;48(1):108-12
references.pmid: 5041870
references.citation: Proc Natl Acad Sci U S A. 2007 Jan 2;104(1):359-64
references.pmid: 17185412
references.citation: Crit Rev Immunol. 2010;30(2):167-87
references.pmid: 20370628
references.citation: Biochem J. 1959 Aug;72:694-706
references.pmid: 13844484
references.citation: Naunyn Schmiedebergs Arch Pharmacol. 1979 Jul;308(1):67-70
references.pmid: 492355
references.citation: Nat Struct Mol Biol. 2007 Jan;14(1):9-10
references.pmid: 17203068
references.citation: Toxicon. 1982;20(1):141-8
references.pmid: 7043781
references.citation: J Protein Chem. 1999 Jan;18(1):89-95
references.pmid: 10071933
references.citation: J Biol Chem. 2012 Nov 23;287(48):40806-16
references.pmid: 23027864