작성일 : 16-02-03
[Accelagen] lambda Protein Phosphatase (λPPase)


lambda Protein Phosphatase (λPPase)



Lambda protein phosphatase (λPPase) is a Mn2+ dependent protein phosphatase with activity to remove

phosphate groups from serine, threonine, tyrosine, and histidine residues. It is the 221 amino-acid product of

the ORF221 open reading frame of bacteriophage lambda (1). Recombinant λPPase is purified from a strain of

E. coli that carries the λPPase gene. λPPase has minimum 95% purity with a molecular weight of 25 kDa as

determined by SDS-PAGE and Coomassie Blue staining. It has no detectable protease and nuclease activity.



Protein Type:

Peotein phosphatase



E. coli


Specific Activity:

>600,000 units/mg

1 unit of λPPase hydrolyzes 1 nmol of p-nitrophenyl phosphate per minute at 30°C in assay buffer of 50 mM

HEPES pH 7.5, 100 mM NaCl. 2 mM DTT, and 1 mM MnCl2.



25 mM HEPES, pH 7.5, 100 mM NaCl, 0.1 mM MnCl2, 0.1 mM EGTA, pH 8.0, 2 mM DTT, 50% glycerol.

The Storage Buffer has no detergent.


Dephosphrylation Procedure

Optimal dephosphorylation condition for a particular protein substrate must be determined empirically. The

phosphatase activity of λPPase varies on protein substrates. No special buffer is required to carry out the

dephosphorylation reaction. Buffers that keep protein substrates stable are recommended. Including 0.1-1

mM MnCl2 will help the dephosphorylation reaction. The dephosphorylation reaction can be carried out at

30oC or 4oC.

Initial dephosphorylation test can be done with 10,000 units of λPPase to 1 mg of target protein at the target

protein concentration of 1-2 mg/ml in a buffer suitable for the target protein at 4oC overnight or 30oC for 30

min. Often, regular SDS-PAGE does not separate phosphorylated and dephosphorylated target protein. Other

detection methods are required to access the dephosphorylation efficiency.

Dephosphorylation can be done at the same time of affinity tag removal during protein purification.


Inactivation of λPPase

λPPase can be heat inactivated at 65oC for 1 hour in the presence of 50 mM EDTA. It is also inhibited by

general protein phosphatase inhibitors such as vanadate.

λPPase has no affinity tag and cannot be easily removed.



Store at below -70oC. Shipped with dry ice.



1.Cohen, P.T.W. and Cohen, P. (1989) Biochem. J. 260:931–934.

2.Zhuo, S. et al. (1993) J. Biol. Chem. 268:17754–17761.



Ordering information


Catalog No.

Product Name



lambda Protein Phosphatase (λPPase), 400,000 units/ml

100,000 units



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