Taylor, Mark A. J. and Baker, Kenneth C. and Briggs, Geoffrey S. and Connerton, I.F. and Cummings, Nicola J. and Pratt, Kathryn A. and Revell, D.F. and Freedman, Robert B. and Goodenough, Peter W. (1995) Recombinant Pro-Regions From Papain And Papaya Proteinase Tv Are Selective High-Affinity Inhibitors Of The Mature Papaya Enzymes. Protein Engineering, 8 (1). pp. 59-62. ISSN 0269-2139. (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)
Proteolytic enzymes require the presence of their pro-regions for correct folding, Of the four proteolytic enzymes from Carica papaya, papain and papaya proteinase IV (PPIV) have 68% sequence identity. We find that their pro-regions are even more similar, exhibiting 73.6% identity, cDNAs encoding the pro-regions of these two proteinases have been expressed in Escherichia coli independently from their mature enzymes, The recombinant pro-regions of papain and PPIV have been shown to be high affinity inhibitors of ah four of the mature native papaya cysteine proteinases, Their inhibition constants are in the range 10(-6)-10(-9) M, PPIV was inhibited two to three orders of magnitude less effectively than papain, chymopapain and caricain, The pro-region of PPIV, however, inhibited its own mature enzyme more effectively than did the proregion of papain, Alignment of the sequences of the four papaya enzymes shows that there is a highly variable section towards the C-terminal of the pro-region, This region may therefore confer selectivity to the pro-regions for the individual proteolytic enzymes.
|Uncontrolled keywords:||Cysteine, Proteinse; Inhibition; Papain; PPIV; Progrgion|
|Divisions:||Faculties > Science Technology and Medical Studies > School of Biosciences|
|Depositing User:||I.T. Ekpo|
|Date Deposited:||25 Oct 2009 12:59|
|Last Modified:||17 Jun 2014 08:43|
|Resource URI:||https://kar.kent.ac.uk/id/eprint/19089 (The current URI for this page, for reference purposes)|