skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Effects of leupeptin on proteinase and germination of castor beans

Abstract

Leupeptin, tripeptide inhibitor of some proteinases, was shown previously to maintain the stability of several enzymes (isocitrate lyase, fumarase, and catalase) in crude extracts of castor bean endosperm. This reagent is now shown to inhibit the breakdown of water-soluble and crystalloid-storage proteins of the protein bodies isolated from castor beans by the SH-proteinase and it also inhibits the endopeptidase from mung beans. When suitably introduced into the endosperm of dry castor beans it strongly inhibits germination and seedling development. Application of leupeptin to endosperm halves removed from the seed prevents the normal development of enzymes concerned with gluconeogenesis from fat and drastically curtails sugar production. The results suggest that the SH-proteinase is intimately involved in the mobilization of storage proteins.

Authors:
;
Publication Date:
Research Org.:
Univ. of California, Sarta Cruz
OSTI Identifier:
5927897
DOE Contract Number:
AS03-76SF00034
Resource Type:
Journal Article
Resource Relation:
Journal Name: Plant Physiol.; (United States); Journal Volume: 68:4
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; CASTOR; GERMINATION; ENZYME ACTIVITY; INHIBITION; ENZYME INHIBITORS; BIOLOGICAL EFFECTS; PLANT GROWTH; EXPERIMENTAL DATA; DATA; GROWTH; INFORMATION; MEDICINAL PLANTS; NUMERICAL DATA; PLANTS; 550200* - Biochemistry

Citation Formats

Alpi, A., and Beevers, H. Effects of leupeptin on proteinase and germination of castor beans. United States: N. p., 1981. Web. doi:10.1104/pp.68.4.851.
Alpi, A., & Beevers, H. Effects of leupeptin on proteinase and germination of castor beans. United States. doi:10.1104/pp.68.4.851.
Alpi, A., and Beevers, H. Thu . "Effects of leupeptin on proteinase and germination of castor beans". United States. doi:10.1104/pp.68.4.851.
@article{osti_5927897,
title = {Effects of leupeptin on proteinase and germination of castor beans},
author = {Alpi, A. and Beevers, H.},
abstractNote = {Leupeptin, tripeptide inhibitor of some proteinases, was shown previously to maintain the stability of several enzymes (isocitrate lyase, fumarase, and catalase) in crude extracts of castor bean endosperm. This reagent is now shown to inhibit the breakdown of water-soluble and crystalloid-storage proteins of the protein bodies isolated from castor beans by the SH-proteinase and it also inhibits the endopeptidase from mung beans. When suitably introduced into the endosperm of dry castor beans it strongly inhibits germination and seedling development. Application of leupeptin to endosperm halves removed from the seed prevents the normal development of enzymes concerned with gluconeogenesis from fat and drastically curtails sugar production. The results suggest that the SH-proteinase is intimately involved in the mobilization of storage proteins.},
doi = {10.1104/pp.68.4.851},
journal = {Plant Physiol.; (United States)},
number = ,
volume = 68:4,
place = {United States},
year = {Thu Oct 01 00:00:00 EDT 1981},
month = {Thu Oct 01 00:00:00 EDT 1981}
}
  • Recent years have seen an increase in the forensic interest associated with the poison ricin, which is extracted from the seeds of the Ricinus communis plant. Both light element (C, N, O, and H) and strontium (Sr) isotope ratios have previously been used to associate organic material with geographic regions of origin. We present a Bayesian integration methodology that can more accurately predict the region of origin for a castor bean than individual models developed independently for light element stable isotopes or Sr isotope ratios. Our results demonstrate a clear improvement in the ability to correctly classify regions based onmore » the integrated model with a class accuracy of 6 0 . 9 {+-} 2 . 1 % versus 5 5 . 9 {+-} 2 . 1 % and 4 0 . 2 {+-} 1 . 8 % for the light element and strontium (Sr) isotope ratios, respectively. In addition, we show graphically the strengths and weaknesses of each dataset in respect to class prediction and how the integration of these datasets strengthens the overall model.« less
  • Intact protein bodies were isolated from dry castor bean seeds (Ricinus communis L.) after homogenization in nonaqueous medium. After repeated washing with glycerol to remove trapped lipid globules, the soluble matrix proteins were removed by the addition of aqueous buffer. The membrane remained attached to the insoluble protein crystalloids and was subsequently released by sonication. Purification of the membrane vesicles in a sucrose gradient produced a single band at a density of 1.21 grams per cubic centimeter. Treatment with 6 molar urea, 1 molar KCl, or 0.25 molar galactose had no effect on the equilibrium density of the membrane. Electronmore » microscopy revealed a highly pure and uniform collection of membrane vesicles. No enzyme activity was specifically associated with the membrane. Sodium dodecyl sulfate gel electrophoresis of the protein body fractions showed that the membrane contained unique proteins, two of which were glycosylated. The membrane contained 153 nanomoles of phospholipid per milligram of protein. The composition of the phosphoglycerides was 51% ethanolamine, 41% choline, 8% inositol, and a trace of serine.« less
  • Recenmore » t years have seen an increase in the forensic interest associated with the poison ricin, which is extracted from the seeds of the Ricinus communis plant. Both light element (C, N, O, and H) and strontium (Sr) isotope ratios have previously been used to associate organic material with geographic regions of origin. We present a Bayesian integration methodology that can more accurately predict the region of origin for a castor bean than individual models developed independently for light element stable isotopes or Sr isotope ratios. Our results demonstrate a clear improvement in the ability to correctly classify regions based on the integrated model with a class accuracy of 60.9 ± 2.1 % versus 55.9 ± 2.1 % and 40.2 ± 1.8 % for the light element and strontium (Sr) isotope ratios, respectively. In addition, we show graphically the strengths and weaknesses of each dataset in respect to class prediction and how the integration of these datasets strengthens the overall model.« less
    Cited by 2