Premium
Stability and reaction characteristics of reverse‐phase evaporation vesicles (REVs) as enzyme containers
Author(s) -
Sada Eizo,
Katoh Shigeo,
Terashima Masaaki,
Shiraga Hiroshi,
Miura Yasushi
Publication year - 1990
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260360703
Subject(s) - chemistry , divalent , vesicle , osmotic pressure , enzyme , bilayer , aqueous solution , membrane , biophysics , biochemistry , organic chemistry , biology
The ion‐dependent enzymes, activities of which are affected by ions, were entrapped in the inside aqueous phase of reverse‐phase evaporation vesicles (REVs) to protect the enzyme activities from inhibitory cations. Their activities were still preserved in the presence of the inhibitory cations because the permeabilities of the inhibitory cations through the lipid membranes of REVs were much lower than those of substrates and products. The REVs were relatively stable in hypertonic condition, while they were unstable in hypotonic condition. Changes in osmotic pressure difference largely affected solute permeabilities of REVs. The shrinking and swelling of REVs resulting from osmotic pressure differences led to these changes in stabilities and solute permeabilities. Although the entrapment of the enzyme into REVs showed good protective effects against divalent cations, it was not effective against univalent cations. The measurements of cation permeabilities revealed that the enzyme trapped in the bilayer regions of REVs acts as a selective channel for the univalent cations. The REVs containing the enzyme could be used without any activity losses in a hollow fiber module.