Phosphodiesterase II

Blue Ice

Molecular Biology Grade

38220090

Spleen exonuclease (Phosphodiesterase II) hydrolyzes 3'-phosphomononucleotides from oligonucleotides containing a 5'-hydroxyl terminus. The enzyme's specificity for the 5'-phosphate end of a polynucleotide chain after conversion to 5'-OH by use of E. coli alkaline phosphatase makes spleen exonuclease very important in the characterization of polynucleotide chain length, base composition and identity of terminal nucleotide.

Spleen exonuclease splits off, sequentially, nucleoside 3'-phosphates, starting at the 5'-OH end, from ribo-or deoxyribo-oligonucleotides. RNA “core”, alkali-treated DNA, poly(A), poly(U), and poly(I) are acted upon. Prior removal of the 5'-terminal phosphate group is essential.

Unit Definition:
1 unit increases the absorbance at 260 nm by 0.200 in 30 minutes at 37°C, pH 6.5, with an RNA Core as substrate.

Optimum pH:
5.5 using succinate and phosphate buffer and an acid DNase digest; pH 6-7 with 0.1M acetate buffer.

Activity:
≥10 units per vial

Units/mg (dry weight):
≥1.2u/mg dw

A280/mg:
~0.3

% ADA:
~1%

Quality Control:
SDS-PAGE

Specificity:
Native DNA and poly(C) are quite resistant. Bis-(p-nitrophenyl) phosphate is a very poor substrate.

Storage and Stability:
Lyophilized powder may be stored at -20°C. Stable for 12 months after receipt at -20°C. Reconstitute with sterile ddH2O. Aliquot to avoid repeated freezing and thawing. Store at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.

Certificate of Origin:
The raw animal product (bovine spleen) used in the manufacturing of Phosphodiesterase II is derived from materials originating in North America and collected in USDA approved facilities and inspected to be free of disease.