Enhanced Heat Stability of α-Chymotrypsin through Single-Enzyme Confinement in Attoliter Liposomes

Chembiochem. 2016 Jul 1;17(13):1221-4. doi: 10.1002/cbic.201600150. Epub 2016 May 12.

Abstract

The entrapment of α-chymotrypsin (α-CT) within 70-140 nm liposomes formed from POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) leads to an unexpected and remarkable increase in the thermal stability of the enzyme. This finding is based on the observation that heating aqueous suspensions of α-CT-containing POPC liposomes to 80 °C for 30 minutes resulted in partial enzyme inactivation, whereas the same treatment of aqueous solutions of free α-CT inactivated the enzyme completely. The stabilizing effect of enzyme confinement in the attoliter volumes of the liposomes was found to increase with decreasing numbers of α-CT molecules per liposome. Single-enzyme confinement was particularly effective, as intermolecular interactions between heat-denatured α-CT molecules (causing irreversible inactivation) are not possible.

Keywords: chymotrypsin; compartment; enzymes; liposomes; stability; vesicles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aniline Compounds / analysis
  • Animals
  • Ascomycota / enzymology
  • Cattle
  • Chymotrypsin / chemistry*
  • Endopeptidase K / chemistry
  • Heating
  • Oligopeptides / chemistry
  • Particle Size
  • Phosphatidylcholines / chemistry
  • Protein Stability
  • Unilamellar Liposomes / chemistry*

Substances

  • Aniline Compounds
  • Oligopeptides
  • Phosphatidylcholines
  • Unilamellar Liposomes
  • 4-nitroaniline
  • succinyl-alanyl-alanyl-prolyl-phenylalanine-4-nitroanilide
  • Chymotrypsin
  • alpha-chymotrypsin
  • Endopeptidase K
  • 1-palmitoyl-2-oleoylphosphatidylcholine