Structure, stability, and activity of myoglobin adsorbed onto phosphate-grafted zirconia nanoparticles.
The adsorption of myoglobin (Mb) onto phosphate grafted-zirconia (ZrO2-P) nanoparticles was studied in terms of conformational studies and thermal stability, determined by circular dichroism (CD), differential scanning calorimetry (DSC), and atomic force microscopy (AFM). The changes in protein structure have been correlated with the catalytic activity of free and adsorbed Mb. CD and DSC studies indicate marked rearrangements in Mb structure upon adsorption onto phosphate-grafted zirconia nanoparticles. These structural rearrangements of Mb could be responsible for the loss of catalytic activity observed for the adsorbed Mb. In particular, the conformational changes due to the adsorption process induced a reduction of kcat and KM. AFM measurements indicate that the interaction with the grafted-zirconia nanoparticles also affects the morphology of the bound protein, inducing the nucleation of prefibrillar-like aggregates.
Bellezza
Francesca
F
Centro di Eccellenza Materiali Innovativi Nanostrutturati (CEMIN), Dipartimento di Chimica, Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy.
Cipiciani
Antonio
A
Quotadamo
Maria Anna
MA
Cinelli
Stefania
S
Onori
Giuseppe
G
Tacchi
Silvia
S
D000327:Adsorption; D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D053768:Metal Nanoparticles; D018625:Microscopy, Atomic Force; D009211:Myoglobin / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D011487:Protein Conformation; D013056:Spectrophotometry, Ultraviolet; D015040:Zirconium / Q000737:chemistry*
D009211:Myoglobin; D010710:Phosphates; D015040:Zirconium