amazing stability of restriction enzymes

Bradley Turner bsturner at
Thu Jun 21 10:54:55 EST 2001

On Thu, 21 Jun 2001, Dr. Duncan Clark wrote:

> In article <v04011702b756adcee64d@[]>, the eminent Michael
> L. Sullivan at BIOSCI/MRC Human Genome Mapping Project Resource Centre
> wrote
> >Thanks for the interesting info.  I (and I'm sure lots of others) have
> >always been under the impression that restriction enzymes are so delicate
> >they will surely lose activity if we look at them the the wrong way, since
> >most of the people who taught me were so paranoid about even having enzymes
> >at ice temp for more than a few min.
> However don't forget that most enzymes are 10-25u/ul and even if you
> killed 75%, given how no one accurately pipettes 0.5ul or whatever,
> there will invariably be enough to do the job.
> If you want to boost the activity even more try casein and look for a
> reference umpteen years ago in NAR, one of those single sheets. I
> believe it led to an EU patent. Basically the authors found that very
> low levels of casein were enough to increase enzyme activity up to
> 1000fold! It never caught on with the manufacturers though!
> For those hot countries, and Californian's(!) (minding the US patents of
> course), you could always try drying the RE's and other modifying
> enzymes at room temp in trehalose. Look for a paper in Nature
> Biotechnology maybe late 80's early 90's by Quadrant Holdings. Storage
> at room temp with no loss of activity for months and months. 
> Duncan
> -- 
> I've learned that no matter how thin you slice it, there are always two sides.
> Duncan Clark
> DNAmp Ltd.
> Tel: +44(0)1252376288
> FAX: +44(0)8701640382

Hello Duncan,

Okay, I swallowed the bait, my curiosity was piqued.

"Casein is a potent enhancer for restriction enzyme activity"
Dreyer K, Schulte-Holthausen H
Nucleic Acids Research 19(15)4295, 1991 Aug 11
PMID 1651485

"Extended stability of restriction enzymes at ambient
Clark J,  Harrison JC, Mdegela RH, March JB
Biotechniques 29(3)536-8, 540, 542, 2000 Sept
PMID 10997268

"Extraordinary stability of enzymes dried in trehalose:
simplified molecular biology"
Colaco C, Sen S, Thangavelu M, Pinder S, Roser B
(Quadrant Research Foundation)
Biotechnology (NY) 10(9)1007-11, 1992 Sept 
PMID 1369408

Brad Turner

                    Bradley Turner
                Beth Israel Deaconess
                    Medical Center

Harvard Medical School          617-667-1215 phone
Division of Gastroenterology    617-667-2767 fax
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                  Boston University
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