Detection and Characterization of Sorbitol Dehydrogenase from Apple Callus Tissue

Detection and Characterization of Sorbitol Dehydrogenase from Apple Callus Tissue Sorbitol dehydrogenase ( l -iditol:NAD + oxidoreductase, EC 1.1.1.14 ) has been detected and characterized from apple ( Malus domestica cv. Granny Smith) mesocarp tissue cultures. The enzyme oxidized sorbitol, xylitol, l -arabitol, ribitol, and l -threitol in the presence of NAD. NADP could not replace NAD. Mannitol was slightly oxidized (8% of sorbitol). Other polyols that did not serve as substrate were galactitol, myo -inositol, d -arabitol, erythritol, and glycerol. The dehydrogenase oxidized NADH in the presence of d -fructose or l -sorbose. No detectable activity was observed with d -tagatose. NADPH could partially substitute for NADH. Maximum rate of NAD reduction in the presence of sorbitol occurred in tris(hydroxymethyl)aminomethane-HCl buffer (pH 9), or in 2-amino-2-methyl-1,3-propanediol buffer (pH 9.5). Maximum rates of NADH oxidation in the presence of fructose were observed between pH 5.7 and 7.0 with phosphate buffer. Reaction rates increased with increasing temperature up to 60 C. The K m for sorbitol and xylitol oxidation were 86 millimolar and 37 millimolar, respectively. The K m for fructose reduction was 1.5 molar. Sorbitol oxidation was completely inhibited by heavy metal ions, iodoacetate, p -chloromercuribenzoate, and cysteine. ZnSO 4 (0.25 millimolar) reversed the cysteine inhibition. It is suggested that apple sorbitol dehydrogenase contains sulfhydryl groups and requires a metal ion for full activity. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png

Detection and Characterization of Sorbitol Dehydrogenase from Apple Callus Tissue

Loading next page...
 
/lp/american-society-of-plant-biologist/detection-and-characterization-of-sorbitol-dehydrogenase-from-apple-UpFyMFc3Ow
Publisher
American Society of Plant Biologist
Copyright
Copyright © 1979 by the American Society of Plant Biologists
ISSN
1532-2548
eISSN
0032-0889
DOI
10.1104/pp.64.1.69
Publisher site
See Article on Publisher Site

Abstract

Sorbitol dehydrogenase ( l -iditol:NAD + oxidoreductase, EC 1.1.1.14 ) has been detected and characterized from apple ( Malus domestica cv. Granny Smith) mesocarp tissue cultures. The enzyme oxidized sorbitol, xylitol, l -arabitol, ribitol, and l -threitol in the presence of NAD. NADP could not replace NAD. Mannitol was slightly oxidized (8% of sorbitol). Other polyols that did not serve as substrate were galactitol, myo -inositol, d -arabitol, erythritol, and glycerol. The dehydrogenase oxidized NADH in the presence of d -fructose or l -sorbose. No detectable activity was observed with d -tagatose. NADPH could partially substitute for NADH. Maximum rate of NAD reduction in the presence of sorbitol occurred in tris(hydroxymethyl)aminomethane-HCl buffer (pH 9), or in 2-amino-2-methyl-1,3-propanediol buffer (pH 9.5). Maximum rates of NADH oxidation in the presence of fructose were observed between pH 5.7 and 7.0 with phosphate buffer. Reaction rates increased with increasing temperature up to 60 C. The K m for sorbitol and xylitol oxidation were 86 millimolar and 37 millimolar, respectively. The K m for fructose reduction was 1.5 molar. Sorbitol oxidation was completely inhibited by heavy metal ions, iodoacetate, p -chloromercuribenzoate, and cysteine. ZnSO 4 (0.25 millimolar) reversed the cysteine inhibition. It is suggested that apple sorbitol dehydrogenase contains sulfhydryl groups and requires a metal ion for full activity.

There are no references for this article.

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create folders to
organize your research

Export folders, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off