- T4 polynucleotide kinase.
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- Description
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- T4 PNK (EC 2.7.1.78) catalyzes the transfer of a
g-phosphate group from a 5´-nucleoside triphosphate moiety
to a free 5´-hydroxyl of a polynucleotide such as DNA or RNA molecule
and a nucleoside-3-monophosphate or deoxynucleoside-3-monophosphate.
Excess of a nucleotide diphosphate such as ADP will cause the reverse
reaction to be favored. That is used in phosphate exchange reaction
for labeling of the DNA or RNA ends.
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- Unit definition
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One unit of the enzyme catalyzes the incorporation of 1 nmol of phosphate
to the 5´-OH end of an oligonucleotide from (g-32P)ATP
in 30 min at 37°C. The enzyme has specific activities in the range
of 30.000-40.000 U/mg.
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- Reaction buffers
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- Tris Kinase Buffer B11 (x10): 500 mM TrisHCl 7.6, 100 mM MgCl2,
50 mM DTT, 1 mM spermindine, 1 mM EDTA.
- Imidazole buffer (for kinasing or phosphate exchange) B12 (x10):
500 mM Imidazole-HCl 6.4, 180 mM MgCl2, 50 mM DTT, 1 mM spermidine,
1 mM EDTA.
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- Reaction conditions
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- The phosphate group donor for the kinase reaction may be any nucleoside
triphosphates at concentration >1 µM. A total of 1.7 mM of spermine
can increase reaction rate by 30-fold. Per reaction use 10-20 U PNK,
1-50 pmol DNA or 10 pmol of oligonucleotide, and 20 pM (g-32P)ATP
(end concentration of ATP should be at least 1µM).
- Tris kinase buffer is used for kinasing of ssDNA fragments, duplexes
with protruding 5´ termini or labeling of oligonucleotides; the
imidasole buffer is used for exchnage reaction and kinasing DNA duplexes
with blunt or recessed 5´ ends. For exchange reaction, ADP and
ATPshould be added at a final conc. of 0,1 mM and 1 nM, respectively.
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- Storage
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- Store at -20°C.
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- Applications
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- phosphorylation of the 5´ termini and end labeling of DNA,
RNA or synthetic oligonucleotides, removal of 3´-phosphoryl groups.
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Quality control
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activity, SDS-PAGE purity, absence of endo- and exonucleases, specific
performance tests.
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References
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1. Richardson, C.C. (1965) Proc. Natl. Acad. Sci. USA 54, 158-163. 2.
van de Sande, J.H. et al. (1973) Biochemistry 12, 5050-5055. 3. Lillehaug,
J.R. et al. (1976) Biochemistry 15, 1858-1865.
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- Catalog #
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- M4.4
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M4.5
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Pack size
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1.000 U
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2.500 U
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