Formation of multistranded β-lactoglobulin amyloid fibrils and their stimuli responsive magnetic behaviour in the lyotropic liquid crystals

Transcription

1 Formation of multistranded β-lactoglobulin amyloid fibrils and their stimuli responsive magnetic behaviour in the lyotropic liquid crystals Sreenath Bolisetty Prof. Raffaele Mezzenga Food & Soft Materials Science ETH, Zurich Switzerland 31 st January

2 Outline 1, Introduction 2, Formation of multistranded β-lactoglobulin Protein fibrils 3, Complexation of β-lactoglobulin Fibrils and Sulfated Polysaccharides 4, Templating effects of lyotropic liquid crystals in the encapsulation of amyloid fibrils and their stimuli-responsive magnetic behavior 5, Conclusions 2

3 1, Introduction β- lactoglobulin 90 C 5 hours ph=2 ph=5.8 ph=7 Jung, J-M et. al Biomacromolecules, 2008, 9,

4 2, Formation of multistranded β-lactoglobulin Protein fibrils Different periodicity of β-lactoglobulin fibrils Multiple filaments are twisting together to form the multistranded Amyloid Fibrils how the filaments are twisting at individual stages during amyloids formation? Adamcik, J.; et. al Nature nanotechnology, 2010, 5,

5 I (q) Small Angle Neutron Scattering 10 After 5hours 1 q q [nm -1 ] Radius of the fibrils=2.1nm Radius of gyration progressively increasing with heating time due to conversion of monomers to larger aggregates. 5

6 Dynamic Light scattering Particle size distribution Depolarized Dynamic Light scattering Sensitive to anisotropic objects provides the rotational diffusion coefficients Bimodal relaxation starts from 15 minutes Monomer to fibril conversion at different heating times is clearly visible Γ VH = Dq 2 +6Θ Θ ~ 1/L 3 Contour length Increasing with heating times. 6

7 Nematic liquid crystalline phase Phase transition from Isotropic phase to nematic liquid crystalline phase Birefringence increases with heating time due to increase in aspect ratio of amyloid fibrils 7

8 Atomic Force Microscopy Images 30 minutes C 45 Minutes Multiple Individual protofilaments are aligned together 8

9 Alignment, twisting of protofilaments self assemble to form the compact multistranded fibrils 9

10 Mature Fibrils at different Ionic strength Periodic pitch resulting from the minimization of electrostatic interactions At high Ionic strength, No pitches were observed 10 10

11 Mature Fibrils Bolisetty, S. et. al Softmatter, 2011, 7,

12 3, Complexation of β-lactoglobulin Fibrils and Sulfated Polysaccharides Electrophoretic mobility before and after complexation Electrophoretic mobility of β- lactoglobulin fibrils changes from positive to negative after complexation with 0.05% of carrageenan 12

13 Transmission electron microscopy Fibril complexation with increasing concentrations of k-carrageenan 0 % % 0.01 % 0.03% 0.05% 13

14 Small angle neutron scattering linear fibrils were sporadically decorated by small, globular particles attached along their contour length. Jones, O. G. Biomacromolecules, 2011, 12,

15 4, Templating effects of lyotropic liquid crystals in the encapsulation of amyloid fibrils and their stimuli-responsive magnetic behavior Phase Diagram of monoglyceride-water system L α Ia3d Pn3m Hex Mezzenga et. Al, Langmuir, 21, 3322 (2005). 15

16 Small-angle X-ray diffraction patterns Mesophases without protein fibrils Mesophases with protein fibrils 16

17 Atomic force microscopy β-lactoglobulin fibrils assembly and confinement in mesophases. A, Lamellar B, Cubic C, Hexagonal 17

18 SANS patterns of mesophases containing protein fibrils coated with iron-oxide magnetic nanoparticles Protein fibrils coated with iron-oxide nanoparticles Amar-Yuli, I. Softmatter, 2011, 7,

19 Optical microscopy images Hexagonal phase with iron oxide coated fibrils with and without magnetic field Lamellar phase with iron oxide coated fibrils with and without magnetic field 19

20 Magnetically driven orientation process of the lyotropic liquid Crystalline phase Vallooran, JJ, Advanced materials, 2011, 23,

21 Acknowledgements & Special Thanks Owen Jones Jozef Adamcik Idit Amar-Yuli Jijo Joy Valloran Stephan Handschin Ludger Harnau Prof. Raffaele Mezzenga Beam time and Support SANS-II, PSI Urs Gasser Sandor Balog Food and Soft Materials group, ETH, Zurich 21

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