BIBLIOS

Document type
Journal articles

Document subtype
Full paper

Title
Extraction of crassulacean acid metabolism-phosphoenolpyruvate carboxylase using aqueous two phase systems

Participants in the publication
A.B. Silva (Author)
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Dep. Biologia Vegetal
BioISI
M.C. Arrabaca (Author)
J.M.S. Cabral (Author)

Summary
The extraction of phosphoenolpyruvate carboxylase (EC 4.1.1.31, PEPC) from Bryophyllum crenatum (Bak.) using aqueous two phase systems was studied. Polyethylene glycol (PEG)/dextran systems were optimized to selectively remove cell debris and chlorophyll, and to recover the enzyme in a single phase. This result was achieved using a 15% (w/v) PEG4000/6% (w/v) dextran T-500 system, with a 100% activity yield. PEPC was recovered in the bottom (dextran) phase, without cell debris and chlorophyll, but the enzyme was not very stable (half-life ≅ 26 h). In the presence of potassium phosphate the partition coefficient of PEPC strongly increased. The back-extraction of the enzyme in the upper phase of a new system was obtained using 7.4% PEG4000/5.6% dextran T-500, with potassium phosphate 0.2 M (PEPC yield of 99%). The half-life of PEPC in the PEG solutions was four-fold higher when compared with the enzyme in the crude extract (half-life ≅ 15 h).


Where published
Plant Science

Publication Identifiers

Publisher
Elsevier BV



Document Identifiers
DOI - https://doi.org/10.1016/0168-9452(91)90214-s
URL - http://dx.doi.org/10.1016/0168-9452(91)90214-s

Keywords
phosphoenolpyruvate carboxylase PEG/dextran systems