TY - JOUR
T1 - Tyrosinase enzyme Langmuir monolayer
T2 - Surface chemistry and spectroscopic study
AU - Paudyal, Suraj
AU - Sharma, Shiv K.
AU - da Silva, Rafael L.C.G.
AU - Mintz, Keenan J.
AU - Liyanage, Piumi Yasodha
AU - Al-Youbi, Abdulrahman O.
AU - Bashammakh, Abdulaziz S.
AU - El-Shahawi, Mohammad S.
AU - Leblanc, Roger M.
N1 - Funding Information:
The authors greatly appreciate the generous funding support provided by National Science Foundation ( NSF), United States, grant # GR-011298 .
Publisher Copyright:
© 2019 Elsevier Inc.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/3/22
Y1 - 2020/3/22
N2 - This study investigates the surface chemistry properties of the tyrosinase enzyme Langmuir monolayer at air-aqueous interface using sodium chloride in the subphase to induce the surface activity of the enzyme. Investigation of surface packing and stability of the tyrosinase Langmuir monolayer were performed using surface chemistry experiments while spectroscopic analysis was done to study enzyme conformation. It was found that the tyrosinase enzyme forms a fluid film at air-aqueous interface with good stability as shown by compression-decompression cycles experiments and stability measurements at various surface pressures. UV-vis absorption and fluorescence measurements at different surface pressures revealed that the Langmuir monolayer has good homogeneity with no evidence of aggregates during compression. To gain insight on the conformation of tyrosinase Langmuir monolayer p-polarized infrared-reflection absorption spectroscopy was used. It was found that at high surface pressures the predominant secondary structures were β-sheets while at lower surface pressure both α -helices and β-sheets were present. The circular dichroism spectra were obtained by transferring the Langmuir monolayer at 10 mN.m−1 to a solid quartz support (Langmuir-Blodgett film, LB film), which showed that the major conformation present were α-helices. Images from the immobilized LB films were obtained using atomic force microscopy which showed homogenous and regular deposition with a mean thickness ranging from 3 to 4 nm.
AB - This study investigates the surface chemistry properties of the tyrosinase enzyme Langmuir monolayer at air-aqueous interface using sodium chloride in the subphase to induce the surface activity of the enzyme. Investigation of surface packing and stability of the tyrosinase Langmuir monolayer were performed using surface chemistry experiments while spectroscopic analysis was done to study enzyme conformation. It was found that the tyrosinase enzyme forms a fluid film at air-aqueous interface with good stability as shown by compression-decompression cycles experiments and stability measurements at various surface pressures. UV-vis absorption and fluorescence measurements at different surface pressures revealed that the Langmuir monolayer has good homogeneity with no evidence of aggregates during compression. To gain insight on the conformation of tyrosinase Langmuir monolayer p-polarized infrared-reflection absorption spectroscopy was used. It was found that at high surface pressures the predominant secondary structures were β-sheets while at lower surface pressure both α -helices and β-sheets were present. The circular dichroism spectra were obtained by transferring the Langmuir monolayer at 10 mN.m−1 to a solid quartz support (Langmuir-Blodgett film, LB film), which showed that the major conformation present were α-helices. Images from the immobilized LB films were obtained using atomic force microscopy which showed homogenous and regular deposition with a mean thickness ranging from 3 to 4 nm.
KW - Infrared reflection-absorption spectroscopy
KW - Langmuir monolayer
KW - Langmuir-Blodgett film
KW - Surface chemistry
KW - Tyrosinase
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U2 - 10.1016/j.jcis.2019.12.118
DO - 10.1016/j.jcis.2019.12.118
M3 - Article
C2 - 31911229
AN - SCOPUS:85078206644
VL - 564
SP - 254
EP - 263
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
SN - 0021-9797
ER -