Microfluidic Diffusion Platform for Characterizing the Sizes of Lipid Vesicles and the Thermodynamics of Protein-Lipid Interactions

Hongze Gang; Céline Galvagnion; Georg Meisl; Thomas Müller; Manuela Pfammatter; Alexander K Buell; Aviad Levin; Christopher M Dobson; Bozhong Mu; Tuomas P J Knowles

doi:10.1021/acs.analchem.7b04820

Microfluidic Diffusion Platform for Characterizing the Sizes of Lipid Vesicles and the Thermodynamics of Protein-Lipid Interactions

Hongze Gang, Céline Galvagnion, Georg Meisl, Thomas Müller, Manuela Pfammatter, Alexander K Buell, Aviad Levin, Christopher M Dobson, Bozhong Mu, Tuomas P J Knowles

12 Citations (Scopus)

Abstract

Elucidation of the fundamental interactions of proteins with biological membranes under native conditions is crucial for understanding the molecular basis of their biological function and malfunction. Notably, the large surface to volume ratio of living cells provides a molecular landscape for significant interactions of cellular components with membranes, thereby potentially modulating their function. However, such interactions can be challenging to probe using conventional biophysical methods due to the heterogeneity of the species and processes involved. Here, we use direct measurements of micron scale molecular diffusivity to detect and quantify the interactions of α-synuclein, associated with the etiology of Parkinson's disease, with negatively charged lipid vesicles. We further demonstrate that this microfluidic approach enables the characterization of size distributions of different binary mixtures of vesicles, which are not readily accessible using conventional light scattering techniques. Finally, the size distributions of the two α-synuclein conformations, free α-synuclein and membrane-bound α-synuclein, were resolved under varying lipid:protein ratios, thus, allowing the determination of the dissociation constant and the binding stoichiometry associated with this protein-lipid system. The microfluidic diffusional sizing platform allows these measurements to be performed on a time scale of minutes using microlitre volumes, thus, establishing the basis for an approach for the study of molecular interactions of heterogeneous systems under native conditions.

Original language	English
Journal	Analytical Chemistry
Volume	90
Issue number	5
Pages (from-to)	3284-3290
Number of pages	7
ISSN	0003-2700
DOIs	https://doi.org/10.1021/acs.analchem.7b04820
Publication status	Published - 6 Mar 2018
Externally published	Yes

Keywords

Diffusion
Microfluidic Analytical Techniques/methods
Particle Size
Phosphatidylethanolamines/metabolism
Phosphatidylserines/metabolism
Protein Binding
Unilamellar Liposomes/chemistry
alpha-Synuclein/chemistry

Access to Document

10.1021/acs.analchem.7b04820

Cite this

@article{6ee3e5ca97324c34ae619a30996b2de4,

title = "Microfluidic Diffusion Platform for Characterizing the Sizes of Lipid Vesicles and the Thermodynamics of Protein-Lipid Interactions",

abstract = "Elucidation of the fundamental interactions of proteins with biological membranes under native conditions is crucial for understanding the molecular basis of their biological function and malfunction. Notably, the large surface to volume ratio of living cells provides a molecular landscape for significant interactions of cellular components with membranes, thereby potentially modulating their function. However, such interactions can be challenging to probe using conventional biophysical methods due to the heterogeneity of the species and processes involved. Here, we use direct measurements of micron scale molecular diffusivity to detect and quantify the interactions of α-synuclein, associated with the etiology of Parkinson's disease, with negatively charged lipid vesicles. We further demonstrate that this microfluidic approach enables the characterization of size distributions of different binary mixtures of vesicles, which are not readily accessible using conventional light scattering techniques. Finally, the size distributions of the two α-synuclein conformations, free α-synuclein and membrane-bound α-synuclein, were resolved under varying lipid:protein ratios, thus, allowing the determination of the dissociation constant and the binding stoichiometry associated with this protein-lipid system. The microfluidic diffusional sizing platform allows these measurements to be performed on a time scale of minutes using microlitre volumes, thus, establishing the basis for an approach for the study of molecular interactions of heterogeneous systems under native conditions.",

keywords = "Diffusion, Microfluidic Analytical Techniques/methods, Particle Size, Phosphatidylethanolamines/metabolism, Phosphatidylserines/metabolism, Protein Binding, Unilamellar Liposomes/chemistry, alpha-Synuclein/chemistry",

author = "Hongze Gang and C{\'e}line Galvagnion and Georg Meisl and Thomas M{\"u}ller and Manuela Pfammatter and Buell, {Alexander K} and Aviad Levin and Dobson, {Christopher M} and Bozhong Mu and Knowles, {Tuomas P J}",

year = "2018",

month = mar,

day = "6",

doi = "10.1021/acs.analchem.7b04820",

language = "English",

volume = "90",

pages = "3284--3290",

journal = "Industrial And Engineering Chemistry Analytical Edition",

issn = "0003-2700",

publisher = "American Chemical Society",

number = "5",

}

TY - JOUR

T1 - Microfluidic Diffusion Platform for Characterizing the Sizes of Lipid Vesicles and the Thermodynamics of Protein-Lipid Interactions

AU - Gang, Hongze

AU - Galvagnion, Céline

AU - Meisl, Georg

AU - Müller, Thomas

AU - Pfammatter, Manuela

AU - Buell, Alexander K

AU - Levin, Aviad

AU - Dobson, Christopher M

AU - Mu, Bozhong

AU - Knowles, Tuomas P J

PY - 2018/3/6

Y1 - 2018/3/6

N2 - Elucidation of the fundamental interactions of proteins with biological membranes under native conditions is crucial for understanding the molecular basis of their biological function and malfunction. Notably, the large surface to volume ratio of living cells provides a molecular landscape for significant interactions of cellular components with membranes, thereby potentially modulating their function. However, such interactions can be challenging to probe using conventional biophysical methods due to the heterogeneity of the species and processes involved. Here, we use direct measurements of micron scale molecular diffusivity to detect and quantify the interactions of α-synuclein, associated with the etiology of Parkinson's disease, with negatively charged lipid vesicles. We further demonstrate that this microfluidic approach enables the characterization of size distributions of different binary mixtures of vesicles, which are not readily accessible using conventional light scattering techniques. Finally, the size distributions of the two α-synuclein conformations, free α-synuclein and membrane-bound α-synuclein, were resolved under varying lipid:protein ratios, thus, allowing the determination of the dissociation constant and the binding stoichiometry associated with this protein-lipid system. The microfluidic diffusional sizing platform allows these measurements to be performed on a time scale of minutes using microlitre volumes, thus, establishing the basis for an approach for the study of molecular interactions of heterogeneous systems under native conditions.

AB - Elucidation of the fundamental interactions of proteins with biological membranes under native conditions is crucial for understanding the molecular basis of their biological function and malfunction. Notably, the large surface to volume ratio of living cells provides a molecular landscape for significant interactions of cellular components with membranes, thereby potentially modulating their function. However, such interactions can be challenging to probe using conventional biophysical methods due to the heterogeneity of the species and processes involved. Here, we use direct measurements of micron scale molecular diffusivity to detect and quantify the interactions of α-synuclein, associated with the etiology of Parkinson's disease, with negatively charged lipid vesicles. We further demonstrate that this microfluidic approach enables the characterization of size distributions of different binary mixtures of vesicles, which are not readily accessible using conventional light scattering techniques. Finally, the size distributions of the two α-synuclein conformations, free α-synuclein and membrane-bound α-synuclein, were resolved under varying lipid:protein ratios, thus, allowing the determination of the dissociation constant and the binding stoichiometry associated with this protein-lipid system. The microfluidic diffusional sizing platform allows these measurements to be performed on a time scale of minutes using microlitre volumes, thus, establishing the basis for an approach for the study of molecular interactions of heterogeneous systems under native conditions.

KW - Diffusion

KW - Microfluidic Analytical Techniques/methods

KW - Particle Size

KW - Phosphatidylethanolamines/metabolism

KW - Phosphatidylserines/metabolism

KW - Protein Binding

KW - Unilamellar Liposomes/chemistry

KW - alpha-Synuclein/chemistry

U2 - 10.1021/acs.analchem.7b04820

DO - 10.1021/acs.analchem.7b04820

M3 - Journal article

C2 - 29313342

SN - 0003-2700

VL - 90

SP - 3284

EP - 3290

JO - Industrial And Engineering Chemistry Analytical Edition

JF - Industrial And Engineering Chemistry Analytical Edition

IS - 5

ER -

Microfluidic Diffusion Platform for Characterizing the Sizes of Lipid Vesicles and the Thermodynamics of Protein-Lipid Interactions

Abstract

Keywords

Access to Document

Fingerprint

Cite this