Table 2: Summary of literature on proteins subjected to conformational changes upon interaction with nanoparticle surfaces [7, 8].

NP type and size Protein investigated Change in protein structure Analytical technique Observations

ZnO NPs (25 nm) Vibrio cholera Tox rYesCDNP-protein complex susceptible to denaturation

ZnO NPs (N/A) BSAYesCDMinor conformational changes, secondary structure retained

ZnO NPs (N/A) BSAYesFTIRMinor conformational changes in secondary structure

TiO2 NPs (20 nm) TubulinYesFSProtein polymerization affected

SiO2 NPs ( 40) nm BSAYesRSBSA and lactoperoxidase bound irreversibly
Hen egg lysozymeNo
RNASe ANo
LactoperoxidaseYes

SiO2 NPs (6,9,15 nm) Human Carbonic anhydraseYesNMRProtein activity was retained

Alumina and hydroxyapatite Particles(100-300nm) BSAYesFTIRLoss in α-helical structure
Hen egg lysozymeYes
Bovine serum fibrinogenYes

Gold (45 nm) BSAYesCDConformational change was dose dependent

Gold (5-100 nm) AlbuminYesCD and FSMinor conformational changes observed
FibrinogenYes
ɣ-globulinYes
Histone H3Yes
InsulinYes

Gold (7-22 nm) Human FibrinogenYesCDUnfolding induced immune response in THP-1 cells

SPIONs (5-10 nm) TransferrinYesCDIrreversible interaction

SWCNTs (N/A) Horse radish peroxidiseNoCDNP-protein complexes retained enzymatic activity
Subtilisin CarlsbergNo
Chicken egg white lysozymeNo
LaccaseYes