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Table 1 Effect of various fatty acids on recombinant Ppt1p activity

From: Characterization of Saccharomyces cerevisiae protein Ser/Thr phosphatase T1 and comparison to its mammalian homolog PP5

Lipid added Carbon chain Relative Activitya TPR protection
   Casein MBP  
Arachidonic acid 20:4 1.3 ± 0.0 13 ± 0.5 +
Arachidic acid 20:0 0.6 ± 0.1 0.8 ± 0.3 -
Arachidonyl alcohol 20:4 0.7 ± 0.1 1.1 ± 0.1 -
Arachidonic methyl ester 20:4 0.7 ± 0.1 0.6 ± 0.2 -
Oleic acid 18:1 1.0 ± 0.1 16 ± 1.0 +
Linoleic acid 18:2 1.0 ± 0.1 21 ± 1.3 +
Palmitoleic acid 16:1 1.0 ± 0.1 20 ± 2.1 +
  1. Phosphatase assays included Ppt1p that was incubated in the presence of various lipids each at a final concentration of 250 μM. Assays also contained either 32P-casein or 32P-MBP. Data are presented as the average activity relative to control in the absence of lipid ± S.D. from a single assay performed in triplicate. This experiment was repeated three times with similar results. The control values for recombinant Ppt1p were as follows: 79 ± 1.9 nmol Pi released minute-1 mg-1 for 32P-casein; 35 ± 10 nmol Pi released minute-1 mg-1 for 32P-MBP. A positive score for TPR protection indicates the sustained presence of multiple proteolytic fragments in the size range of 14 to 16 kDa after either trypsin or subtilisin digestion when compared to the control digest containing vehicle. aRatio of phosphatase activity in the presence of 250 μM of the lipid indicated to the phosphatase activity without lipid.