Large scale purification of myo‐inositol monophosphate phosphatase from porcine brains

Francis Kwok, Xing Hua Wang, Christopher H.K. Cheng, Chun Lap Samuel Lo

Research output: Journal article publicationJournal articleAcademic researchpeer-review

2 Citations (Scopus)


myo‐Inositol monophosphate phosphatase (IMPase) has been purified 888‐fold to apparent homogeneity from procine brains. The purification procedure involves: homogenization, ammonium sulfate fractionation, and a number of ion‐exchange and gel‐filtration chromatography steps. The purified enzyme exhibited a final specific activity of 932 nmol · min−1 · mg−1. The molecular mass of the enzyme was estimated to be 29kDa by SDS poly‐acrylamide gel electrophoresis and 58 ± 5 kDa by HPLC gel filtration in 10mM Tris‐HCI, pH 7.4. Kinetic measurements have shown that the apparent Km value of the phosphatase for the utilization of inositol‐1‐phosphate and β‐glycerol phosphate are 3.20 × 10−4 and 8 × 10−3 M, respectively. Similar to the same enzyme isolated from bovine brains, the porcine brain enzyme has been shown to be inhibited by lithium. The K1 was determined to be 6.38 × 10−4 M and the inhibition is uncompetitive.
Original languageEnglish
Pages (from-to)542-546
Number of pages5
JournalBiotechnology and Bioengineering
Issue number5
Publication statusPublished - 1 Jan 1995


  • inositol monophosphatase
  • lithium
  • purification

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Applied Microbiology and Biotechnology


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