Lactate dehydrogenase in interpolyelectrolyte complex. Function and stability

M. E. Bobreshova, G. B. Sukhorukov, E. A. Saburova, L. I. Elfimova, L. I. Shabarchina, B. I. Sukhorukov

Research output: Contribution to journalArticlepeer-review

36 Citations (Scopus)

Abstract

A new method for encapsulating enzymes by multilayer polyelectrolyte coating is proposed. The method consists in a stepwise adsorption of polyelectrolytes from solution onto protein aggregates formed by salting out the proteins in highly concentrated salt solutions. Polystyrene sulfonate and fluorescence-labeled polyalylamine were used for capsule formation. The size of lactate dehydrogenase aggregates covered by four layer pairs of electrolytes was 1-5 μm, as indicated by fluorescence microscopy. The catalytic characteristics and stability of pig muscle lactate dehydrogenase (EC 1.1.1.13) incapsulated in multilayer electrolyte complex obtained by this method were studied. It was found that the affinity of the substrate pyruvate for the enzyme in the polyelectrolyte complex (KM) did not essenstially change as compared with the free enzyme. Incapsulated lactate dehydrogenase showed the following features that distinguish it from the free form: (1) the lifetime in diluted solutions increases from 30 min (without capsules) to 1-2 days (in capsules); (2) a higher stability to basic denaturation (up to pH 10); and (3) the absence of substrate inhibition of enzyme in the polyelectrolyte complex. The changes in the catalytic characteristics of incapsulated lactate dehydrogenase are discussed in terms of an increase in effective pK values of amino acid perturbed by polyelectrolyte coating of enzyme.

Original languageEnglish
Pages (from-to)819-820
Number of pages2
JournalBiofizika
Volume44
Issue number5
Publication statusPublished - 1999
Externally publishedYes

Keywords

  • Enzymic catalysis
  • Lactate dehydrogenase
  • pH optimum
  • Polyelectrolytes
  • Stability

Fingerprint

Dive into the research topics of 'Lactate dehydrogenase in interpolyelectrolyte complex. Function and stability'. Together they form a unique fingerprint.

Cite this