Structural Characterization of Myoglobin Molecules Adsorbed within Mesoporous Silicas

• Published in: Journal of physical chemistry. C Vol. 122; no. 27; pp. 15567 - 15574
• Main Authors: Kijima, Jun, Shibuya, Yuuta, Katayama, Kazuya, Itoh, Tetsuji, Iwase, Hiroki, Fukushima, Yoshiaki, Kubo, Minoru, Yamaguchi, Akira
• Format: Journal Article
• Language: English
• Published: American Chemical Society 12.07.2018
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.8b04356

In the present study, we examined the secondary and tertiary structure of myoglobin (Mb) within folded sheets mesoporous material (FSM)- and Santa Barbara amorphous (SBA)-type mesoporous silicas. The Barrett–Joyner–Halenda pore diameters of SBA-type mesoporous silicas were 39, 70, and 75 Å, and that of FSM-type mesoporous silica was 40 Å. The secondary and tertiary structures of myoglobin were observed by Fourier transform infrared (FTIR) and small-angle neutron scattering (SANS), respectively. The FTIR and SANS results indicated preservation of the secondary and tertiary structures of myoglobin inside the pores of SBA-type mesoporous silicas. Adsorption of myoglobin within FSM-type mesoporous silica, however, resulted in perturbation of the tertiary structure, accompanied by partial unfolding of the secondary structure. Lower structural stability of myoglobin within the FSM-type mesoporous silica was also confirmed. These findings suggest that the Mb structure is more influenced by the inner pore surface characteristics than by geometrical pore size.