Interaction of nanoparticles with proteins: relation to bio-reactivity of the nanoparticle

Table 2 Summary of literature on proteins subjected to conformational changes upon interaction with nanoparticle surfaces

NP type and size	Protein investigated	Protein mol. wt. and size nm (if provided)	Change in protein structure	Analytical technique	Observations	Ref
ZnO NPs (25 nm)	Vibrio cholera Tox r	32.5 kDa	Yes	CD	NP-protein complex susceptible to denaturation	[40]
ZnO NPs (N/A)	BSA	66 kDa	Yes	CD	Minor conformational changes, secondary structure retained	[31]
ZnO NPs (N/A)	BSA	66 kDa	Yes	FTIR	Minor conformational changes in secondary structure	[42]
TiO₂ NPs (20 nm)	Tubulin	55kda	Yes	FS	Protein polymerization affected	[30]
SiO₂ NPs (~40 nm)	BSA	66 kDa	Yes	RS	BSA and lactoperoxidase bound irreversibly	[33]
	Hen egg lysozyme	14.3 kDa	No
	RNASe A	13.7 kDa	No
	Lactoperoxidase	77.5 kDa	Yes
SiO₂ NPs (6,9,15 nm)	Human Carbonic anhydrase	29 kDa	Yes	NMR	Protein activity was retained	[4]
Alumina and hydroxyapatite particles (100-300 nm)	BSA	66 kDa 8 × 8 × 3	Yes	FTIR	Loss in α-helical structure	[43]
	Hen egg lysozyme	14.3 kDa 4.6 × 3 × 3	Yes
	Bovine serum fibrinogen	350 kDa 6 × 6.5 × 45	Yes
Gold (45 nm)	BSA	66 kDa	Yes	CD	Conformational change was dose dependent	[28]
Gold (5-100 nm)	Albumin	67 kDa	Yes	CD and FS	Minor conformational changes observed	[27]
	Fibrinogen	340 kDa	Yes
	ɣ-globulin	120 kDa	Yes
	Histone H3	15 kDa	Yes
	Insulin	5.8 kDa	Yes
Gold (7-22 nm)	Human Fibrinogen	340 kDa 45 × 5	Yes	CD	Unfolding induced immune response in THP-1 cells	[35]
SPIONs (5-10 nm)	Transferrin	80 kDa	Yes	CD	Irreversible interaction	[32]
SWCNTs (N/A)	Horse radish peroxidase	44 kDa	No	CD	NP-protein complexes retained enzymatic activity	[34]
	Subtilisin Carlsberg	39 kDa	No
	Chicken egg white lysozyme	14.3 kDa	No

(Abbreviations used: CD Circular dichroism spectrometry, FTIR Fourier transformed infrared spectrometry, FS Fluorescence spectroscopy, RS Raman spectroscopy, NMR Nuclear magnetic resonance).

ISSN: 1477-3155