Stereochemistry of C-1 hydrogen exchange in the interconversion of trans,trans- and cis,trans-farnesols by soluble enzymes from tissue cultures of Andrographis paniculata

1974 ◽  
pp. 385 ◽  
Author(s):  
Karl H. Overton ◽  
Frank M. Roberts
Keyword(s):  
Hydrogen Exchange ◽  
Andrographis Paniculata ◽  
Tissue Cultures ◽  
Soluble Enzymes

scholarly journals Biosynthesis of trans,trans- and cis,trans-farnesols by soluble enzymes from tissue cultures of Andrographis paniculata

1974 ◽  
Vol 144 (3) ◽  
pp. 585-592 ◽  
Author(s):  
K H Overton ◽  
F M Roberts
Keyword(s):  
Hydrogen Atom ◽  
Alcohol Dehydrogenase ◽  
Chemical Synthesis ◽  
Andrographis Paniculata ◽  
Tissue Cultures ◽  
Trans Isomers ◽  
Free System ◽  
Liver Alcohol Dehydrogenase ◽  
A Cell ◽  
Soluble Enzymes

A cell-free system obtained from tissue cultures of Andrographis paniculata produces 2-trans,6-trans-farnesol (trans, trans-farnesol) and 2-cis,6-trans-farnesol (cis,trans-farnesol) (5:1), incorporating 10% of the radioactivity from 3R-[2-14C]mevalonate. There is total loss of3H from 3RS-[2-14C,(4S)-4-3H1]mevalonate and total retention from the (4R) isomer in both the trans, trans-farnesol and cis,trans-farnesol formed. When 3RS-[2-14C,5-3H2]mevalonate is used as substrate, there is total retention of3H in the trans, trans-farnesol, but loss of one-sixth of the3H in the cis,trans-farnesol. With (1R)- and (1S)-[4,8,12-14C3,1-3H1]-trans, trans -farnesol and (1R)- and (1S)-[4,8,12-14C3,1-3H1]-cis,trans-farnesol as substrates, the label is lost from the (1R)-cis,trans and (1S)-trans, trans isomers but retained in the (1R)-trans, trans and (1S)-cis,trans isomers; this shows that the pro-1S hydrogen is exchanged in the conversion of trans, trans-farnesol into cis,trans-farnesol and the pro-1R hydrogen in the conversion of cis,trans-farnesol into trans, trans-farnesol. (1R)-[1-3H1]-trans, trans-Farnesol and (1R)-[1-3H1]-cis,trans-farnesol have been synthesized by asymmetric chemical synthesis and exchanged with liver alcohol dehydrogenase. Both the trans- and the cis-alcohol exchange the pro-1R hydrogen atom.

Paniculides A, B, and C, bisabolenoid lactones from tissue cultures of Andrographis paniculata

1968 ◽  
pp. 1493 ◽  
Author(s):  
A. J. Allison ◽  
D. N. Butcher ◽  
J. D. Connolly ◽  
K. H. Overton
Keyword(s):  
Andrographis Paniculata ◽  
Tissue Cultures

Cyclisation of farnesyl pyrophosphate to γ-bisabolene in tissue cultures of Andrographis paniculata

1982 ◽  
pp. 268-270 ◽  
Author(s):  
Panayiotis Anastasis ◽  
Isabel Freer ◽  
Christopher Gilmore ◽  
Hugh Mackie ◽  
Karl Overton ◽  
...  
Keyword(s):  
Andrographis Paniculata ◽  
Farnesyl Pyrophosphate ◽  
Tissue Cultures

Stereochemistry of the leucine 2,3-aminomutase from tissue cultures of Andrographis paniculata

1981 ◽  
pp. 80 ◽  
Author(s):  
Isabel Freer ◽  
Giuseppe Pedrocchi-Fantoni ◽  
Douglas J. Picken ◽  
Karl H. Overton
Keyword(s):  
Andrographis Paniculata ◽  
Tissue Cultures

Comparison of Choriocarcinoma and Normal Placenta

1971 ◽  
Vol 29 ◽  
pp. 324-325
Author(s):  
John C. Garancis ◽  
Roland A. Pattillo ◽  
Robert O. Hussa ◽  
Jon V. Straumfjord
Keyword(s):  
Cell Lines ◽  
Small Cells ◽  
Tissue Cultures ◽  
Glycogen Depletion ◽  
Cell Surfaces ◽  
Intercellular Spaces ◽  
Concomitant Increase ◽  
Gestational Choriocarcinoma ◽  
Cytoplasmic Glycogen ◽  
Normal Placenta

Two different cell lines (Be-Wo and Jar) of human gestational choriocarcinoma have been maintained in continuous tissue culture for a period of four and two years respectively without losing the ability to elaborate human chorionic gonadotropin (HCG). Tissue cultures, as revealed by electron microscopy, consisted of small cells with single nuclei. In some instances cell surfaces were provided with microvilli but more often the intercellular spaces were narrow and bridged by desmosomes. However, syncytium was not formed. Endoplasmic reticulum (ER) was poorly developed in both cell lines, except in some Be-Wo cells it was prominent. Golgi complex, lysosomes and numerous free ribosomes, as well as excessive cytoplasmic glycogen, were present in all cells (Fig. 1). Glycogen depletion and concomitant increase of ER were observed in many cells following a single dose of 10 ugm/ml of adrenalin added to medium (Fig. 2).

Scanning Tunneling Microscopy and Atomic Force Microscopy of Enzymes and Enzyme Complexes

1990 ◽  
Vol 48 (3) ◽  
pp. 174-175
Author(s):  
Ronald D. Edstrom ◽  
Xiuru Yang ◽  
Mary E. Gurnack ◽  
Marcia A. Miller ◽  
Rui Yang ◽  
...  
Keyword(s):  
Cell Biology ◽  
Inorganic Ions ◽  
Bulk Liquid ◽  
Soluble Form ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Metabolic Channeling ◽  
Simplistic Notion ◽  
Soluble Enzymes

Many of the questions in biochemistry and cell biology are concerned with the relationships of proteins and other macromolecules in complex arrays which are responsible for carrying out metabolic sequences. The simplistic notion that the enzymes we isolate in soluble form from the cytoplasm were also soluble in vivo is being replaced by the concept that these enzymes occur in organized systems within the cell. In this newer view, the cytoplasm is organized and the “soluble enzymes” are in fact fixed in the cellular space and the only soluble components of the cell are small metabolites, inorganic ions etc. Further support for the concept of metabolic organization is provided by the evidence of metabolic channeling. It has been shown that for some metabolic pathways, the intermediates are not in free diffusion equilibrium with the bulk liquid in the cell but are passed along, more or less directly, from one enzyme to the next.

Freeze-Fracture Studies of Membranes in Developing Sieve Elements in a Plant Tissue Culture

1980 ◽  
Vol 38 ◽  
pp. 636-637
Author(s):  
R. D. Sjolund ◽  
C. Y. Shih
Keyword(s):  
Plant Tissue ◽  
Cultured Cells ◽  
Freeze Fracture ◽  
Tissue Cultures ◽  
Sieve Elements ◽  
Intact Plants ◽  
Plant Tissue Cultures ◽  
Whole Plants ◽  
Energy Dependent ◽  
Similar Elements

The differentiation of phloem in plant tissue cultures offers a unique opportunity to study the development and structure of sieve elements in a manner that avoids the injury responses associated with the processing of similar elements in intact plants. Short segments of sieve elements formed in tissue cultures can be fixed intact while the longer strands occuring in whole plants must be cut into shorter lengths before processing. While iyuch controversy surrounds the question of phloem function in tissue cultures , sieve elements formed in these cultured cells are structurally similar to those of Intact plants. We are particullarly Interested In the structure of the plasma membrane and the peripheral ER in these cells because of their possible role in the energy-dependent active transport of sucrose into the sieve elements.

Sign in / Sign up

Export Citation Format

Share Document