| Value |
0.2
min^-1
|
| Organism |
Unspecified |
| Reference |
Kaddurah-Daouk R, Cho P, Smith HO. Catalytic properties of the HhaII restriction endonuclease. J Biol Chem. 1985 Dec 5260(28):15345-51. p.15349 right column, second paragraphPubMed ID2999112
|
| Method |
Researchers used two different assays in this work. One assay employs
agarose gel electrophoresis to separate DNA product
bands produced by cleavage of plasmid pSKll which contains
a single HhaII site, and the amount of DNA in each band is
determined by ethidium bromide staining and densitometry. The second assay employs pSK11 DNA specifically labeled
with 32P-atoms within the site. HhaII cleavage exposes the
labeled phosphoryl groups which are then released as inorganic
phosphate by phosphatase action. Released radioactive
phosphate is then quantitated by thin layer chromatography. |
| Comments |
The rate constants for the cleavage of the first and second
phosphodiester bonds in a site are a function of enzyme
concentration up to the point where all sites are saturated
with enzyme. At near-saturating conditions and irrespective
of the mode of mixing, the cleavage of each strand follows a
first order reaction with k1=~0.8 (0.76) and k2=~0.2 single strand
scissions/min. |
| Entered by |
Ben Marks |
| ID |
101632 |