Estimation of endoglucanase and lysozyme effective diffusion coefficients in polysulphone membranes

Theodore Varzakas, Isabel Escudero, Ioannis G. Economou

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A diffusion cell and a polysulphone membrane were used for the estimation of the effective diffusion coefficient (D(M)) of endoglucanase and lysozyme. D(M) was calculated from the slope obtained by fitting the amount of protein transferred through the membrane against time using the appropriate mathematical equation for the steady state. Different protein concentrations and pH values were tested. The calculated D(M) for endoglucanase was in the order of 10-13 m2 s-1 whereas the calculated D(M) for lysozyme was an order of magnitude lower. A diffusion coefficient dependence on the concentration and pH was observed. In addition, the partition coefficient, K(M), of the two proteins between the membrane and a solution containing the proteins was calculated. Copyright (C) 1999 Elsevier Science B.V.

Original languageEnglish
Pages (from-to)77-83
Number of pages7
JournalJournal of Biotechnology
Issue number1-2
Publication statusPublished - 11 Jun 1999



  • Effective diffusion coefficients
  • Endoglucanase
  • Lysozyme
  • Polysulphone membranes

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Applied Microbiology and Biotechnology

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