Plant Physiol. Illumina
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Plant Physiology 43:1355-1361 (1968)
© 1968 American Society of Plant Biologists

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Web of Science (48)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hsiao, T. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hsiao, T. C.
Agricola
Right arrow Articles by Hsiao, T. C.
Articles

Ribonuclease Activity Associated With Ribosomes of Zea mays 1

Theodore C. Hsiao2

Department of Agricultural Sciences (Plant Biochemistry), University of California, Los Angeles, California 90024

At pH 6.5, a ribonuclease(s) is associated with ribosomes isolated from corn (Zea mays L.) and cannot be removed by repeated differential centrifugation or by sedimenting through the sucrose gradient. The enzyme is active under conditions favoring the maintenance of integrity of the ribosomes. Little or no latent ribonuclease appears to be present. The activity of the enzyme at pH 5.8 is stimulated by KCl and inhibited by polyvinyl sulfate, zinc, and bentonite. Deoxyribonuclease is also found on the particles.

The enzyme can be removed from ribosomes by adsorption onto bentonite. Ribosomes are also adsorbed but to a much lesser extent at low bentonite concentrations. The enzyme is easily dissociated from ribosomes by raising the pH to 8.5, and readsorbed when the pH is lowered.

The ribonuclease activity on ribosomes shows a sharp increase with cell age that parallels closely the increase in total activity in the homogenate. The ratio of activities of deoxyribonuclease to ribonuclease on ribosomes also changes with cell age and again the changes appear to reflect changes in the homogenate. It is suggested that most of the association of ribonuclease with corn ribosomes may not be meaningful in vivo and occurs only after the cells are ruptured.

2 Present address: Department of Water Science and Engineering. University of California, Davis, California 95616.

1 This research was supported in part by a grant from the Cancer Research Coordinating Committee of the University of California.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ASPB Publications PLANT PHYSIOLOGY® THE PLANT CELL
Copyright © 1968 by the American Society of Plant Biologists