Encapsulation of horseradish peroxidase in water-immiscible coacervates with enhanced of thermostability

Sakhno T.V.1, Korotkova I.V.2, Zvenihorodska T.V.2, Barashkov N.N.3

1Poltava University of Economics and Trade, Kovalya st.,3, Poltava, Ukraine
2Poltava State Agrarian Academy, Skovoroda st., 1/3, Poltava, Ukraine
e-mail: 2irinakorotkova10@gmail.com
3Micro Tracers, Inc, 1370 Van Dyke Avenue, San Francisco, California 94124 USA

Among the various methods for increasing the thermostability of enzymes, the most promising is associated with various types of encapsulation. The enzyme encapsulation can provide a microenvironment that increases thermal stability and promotes enzymatic activity at high temperatures. The main attention is paid to the correlation of thermal stability and activity of enzymes using traditional and new encapsulation schemes, in which various materials, including nanogel, are used [1]. Looking for novel matrix materials for encapsulation of  enzymes based on water-immiscible coacervates prepared by reaction of negatively charged hyaluronic acid (HA) and a positively charged recombinant mussel adhesive protein (rMAP) containing tyrosine residues (rMAP/HA) is the subject of the investigation of this work. We presented the results of experimental improvement of the thermostability of horseradish peroxidase (HRP) by means its "encapsulation" in these coacervates rMAP/HA. To determine thermal stability of the free HRP and rMAP/HA coacervate, containing HRP, the sample was incubated at temperature 30-950C. It was found that the encapsulated enzyme is capable of providing an increase in thermal stability for three minutes at a temperature of up to 950C at pH=7.0. Comparison of the thermal stability of free and "encapsulated" HRP showed that the free enzyme began to lose activity above 400C, while the "encapsulated" HRP remained stable to 850C. The "encapsulated" HRP lost only 18% and 25% of activity at temperatures of 90 and 950C, respectively, while as free HRP loses all its initial activity, although they show similar activity at room temperature. It was concluded that the method of "encapsulating" enzymes using rMAP/HA coacervate is able to provide significantly better results than other known methods of encapsulation.

1.Ming Yan, Jun Ge, Zheng Liu, Pingkai Ouyang. Encapsulation of Single Enzyme in Nanogel with Enhanced Biocatalytic Activity and Stability// J. Am. Chem. Soc. – 2006.  – 128. – P. 11008-11009.