1. Size and coating of nanoparticles have effect on
their thermodynamic interaction with proteins
Seyed Mohammad Motevalli
Fall 2014
1
Shahid Beheshti University
IRAN

2. Outline:
Corona
Hard
Soft
Nanoparticle features:
Size
• SPR
• Shape
• Zeta potential
Coat
• Type
• Charge
• Hydrophobicity
• Density
Protein features:
Molecular weight
Charge
Hydrophobicity
Structures
• Secondary
• Tertiary
Thermodynamically
interaction
Gibbs free energy
Equilibrium constant 2

3.  Corona
Hard
• Nanoparticle
fingerprint
• Less exchange rate
• More affinity
Soft
• Outer layer
• More exchange rate
• Less affinity
3
• W. Liu et al. 2013.
• M. P. Monopoli et al. 2010.
• I. Lynch et al. 2008.

4. Nanoparticle features:
Size
• SPR
The collective oscillation of the
conductive electrons
• Shape
decrement of spherical shape is
usually with blue shift in UV-absorbance
diagram
• Zeta potential
The electric potential at the boundary
of the double layer
4
• V. Juve et al. 2013.
• M. De et al. 2008.
• A. Albanese et al. 2012.
• J. D. Clogston et al. 2011.

5. Nanoparticle features:
Coating
• Type
There are metallic and non-metallic
NPs
• Charge
Different coatings have
different charge (negative-neutral-
positive)
• Hydrophobicity
Based on functional groups
• Density
Density of coating derivatives
effect on protein adsorption
5
• Z. Wang et al. 2009.
• L. Ramajo et al. 2009.
• M. Lundqvist et al. 2008.
• V. Mohanraj et al. 2007.
• C. D. Walkey et al. 2011.

6. • Smaller amino acids
side chain have more
flexibility
• Heavier proteins have
more contact positions
Protein features:
Molecular weight
6
• R. Najmanovich et al. 2000.
• M. Lundqvist et al. 2008.

7. Protein features:
Charge
• Additional protein net
charge, the positional
net charge is important
too
• NP surfaces may take
up proteins depending
on their pI in a rather
narrow pH range
7
• K. H. R. Choo 2008.
• M. Mahmoudi et al. 2011.

8. Protein features:
Hydrophobicity
• Globular proteins have lesser tend to smaller NPs
• Proteins with less than 200 residues usually have more
hydrophobicity
8
• H. Liao et al. 2005.
• J. Klein. 2005.
• Z. Weng et al. 2001.

9.  Secondary
• sheet structure have
more entropy
• Charge amino acids
usually are part of helix
structures
 Tertiary
• Encounter position
• Conserved sequences
have more stability
Protein features:
Structure
9
• W. Yeh. 2005.
• H. Liao et al. 2005.
• H. S. Frank et al. 1945.

10. Thermodynamically interaction:
Gibbs free energy
• Hydrophobic amino
acids usually have
more flexibility
• Smaller NPs have
lesser contact positions
than larger NPs
• Free change Gibbs
energy in larger NP-protein
is more than
smaller ones
Δ퐺 = Δ퐻 − 푇Δ푆
10
• G. D. Rose et al. 1985.
• M. Lundqvist et al. 2008.
• J. M. Hayes et al. 2012.

11. Thermodynamically interaction:
Gibbs free energy
11
• S. T. Yang et al. 2013.

12. Thermodynamically interaction:
 Equilibrium constant
12
• F. D. Sahneh et al. 2013.

13. 13

14. Contact orientation:
14