Related Experiment Video
Updated: May 27, 2026
Hydrophobic Salt-modified Nafion for Enzyme Immobilization and Stabilization
Published on: July 11, 2012
Thermal stabilization of formaldehyde dehydrogenase by encapsulation in liposomes with nicotinamide adenine
Makoto Yoshimoto1, Takayuki Yamashita, Satoshi Kinoshita
1Department of Applied Molecular Bioscience, Yamaguchi University, 2-16-1 Tokiwadai, Ube, 755-8611, Japan. yosimoto@yamaguchi-u.ac.jp
Abstract:
The thermal stability of formaldehyde dehydrogenase (FaDH) from Pseudomonas sp. was examined and controlled by encapsulation in liposomes with β-reduced nicotinamide adenine dinucleotide (NADH). The activity of 4.8 μg/mL free FaDH at pH 8.5 in catalyzing the oxidation of 50mM formaldehyde was highly dependent on temperature so that the activity at 60 °C was 27 times larger than that at 25 °C. Thermal stability of the FaDH activity was examined with and without liposomes composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Rapid deactivation of free FaDH was observed at 60 °C because of its dissociation into two subunits. The rate of dissociative deactivation of POPC liposome-encapsulated FaDH was smaller than that of the free enzyme. The liposomal FaDH was however progressively deactivated for the incubation period of 60 min eventually leading to complete loss of its activity. The free FaDH and NADH molecules were revealed to form the thermostable binary complex. The thermal stability of POPC liposome-encapsulated FaDH and NADH system was significantly higher than the liposomal enzyme without cofactor. The above results clearly show that NADH is a key molecule that controls the activity and stability of FaDH in liposomes at high temperatures.
