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.

Thermolability of protein synthesis in a cell-free system from the obligately psychrophilic yeast Candida gelida

1969 ◽  
Vol 15 (4) ◽  
pp. 339-343 ◽  
Author(s):  
C. H. Nash ◽  
D. W. Grant ◽  
N. A. Sinclair
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Thermal Inactivation ◽  
Kinetic Studies ◽  
Temperature Sensitive ◽  
Free System ◽  
Psychrophilic Yeast ◽  
A Cell ◽  
Polypeptide Chains ◽  
Soluble Enzymes

A subcellular amino-acid-incorporating system from the obligately psychrophilic yeast, Candida gelida, was completely inhibited after incubation at 35 C for 30 minutes. The thermal inactivation of protein synthesis was due, in part, to the presence of unusually temperature-sensitive aminoacyl-sRNA synthetases in C. gelida extracts. Of the 13 specific synthetases examined, 7 retained less than 50% of their activity after being held at 35 C for 30 minutes. Kinetic studies of thermal inactivation of leucyl-sRNA synthetase demonstrated that this enzyme is 50% inactivated after only 7 minutes at 35 C. None of the 10 sRNA species tested was temperature sensitive. In addition to temperature-sensitive synthetases, C. gelida possesses thermolabile soluble enzymes involved in the formation of ribosomal-bound polypeptide chains.

scholarly journals Stereochemistry of allene biosynthesis and the formation of the acetylenic carotenoid diadinoxanthin and peridinin (C37) from neoxanthin

1981 ◽  
Vol 199 (1) ◽  
pp. 69-74 ◽  
Author(s):  
I E Swift ◽  
B V Milborrow
Keyword(s):  
Hydrogen Atom ◽  
Beta Carotene ◽  
Intact Cells ◽  
Amphidinium Carterae ◽  
Free System ◽  
Cell Free System ◽  
A Cell

Intact cells of the alga Amphidinium carterae (Dinophyceae), and a cell-free system prepared from it, incorporated 14C, 3H-labelled mevalonate into lycopene, beta, beta-carotene, zeaxanthin, neoxanthin, diadinoxanthin and peridinin. The 14C/3H ratios of zeaxanthin, neoxanthin and diadinoxanthin formed from (2RS,3R)-[2-14C,2-3H2]mevalonate show that a hydrogen atom from C-2 of mevalonate is retained in the allene at C-8, and also at C-12 of peridinin. (3R,4R + 3S,4S)-[2-14C,4-3H1]Mevalonate gave 14C/3H ratios in peridinin which show that C-14 is lost. The three carbon atoms excised during the formation of the C37 carotenoid peridinin are C-13, C-14 and C-20 of neoxanthin.

EXAFS INVESTIGATION OF THE STRUCTURAL SITE OF LIVER ALCOHOL DEHYDROGENASE

1986 ◽  
Vol 47 (C8) ◽  
pp. C8-1165-C8-1168
Author(s):  
M. ZEPPEZAUER ◽  
C. HAAS ◽  
W. MARET ◽  
C. HERMES ◽  
R. F. PETTIFER
Keyword(s):  
Alcohol Dehydrogenase ◽  
Liver Alcohol Dehydrogenase ◽  
Structural Site
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