Extraction of alcohol dehydrogenase from fresh root tips of loblolly pine

1986 ◽  
Vol 16 (1) ◽  
pp. 146-148 ◽  
Author(s):  
Stewart Denslow ◽  
Donal D. Hook
Keyword(s):  
Enzyme Activity ◽  
Alcohol Dehydrogenase ◽  
Liquid Nitrogen ◽  
Loblolly Pine ◽  
Chromatographic Purification ◽  
Root Tips ◽  
Protective Measures ◽  
Quick Freezing ◽  
Complete Homogenization ◽  
Plant Components

Significant alterations of published methods for extracting alcohol dehydrogenase from plant components were required to obtain measurable enzyme activity from actively growing root tips of loblolly pine (Pinustaeda L.). Necessary steps were quick freezing of roots in liquid nitrogen within 5 min of excising, use of soluble polyvinylpyrrolidone during freezing and fracturing in liquid nitrogen, and use of mercaptoethanol, glycerol, and NAD as protective measures during complete homogenization. No chromatographic purification steps were necessary. Up to 16 samples could be collected and analyzed in a single day by this method with sufficient sensitivity to detect intraspecific variation among loblolly pine families.

Glycosyltransferases in plant and animal tissues effects of fixation and lead on enzyme activity.

1978 ◽  
Vol 26 (10) ◽  
pp. 772-781 ◽  
Author(s):  
W D Klohs ◽  
C W Goff ◽  
R J Bernacki
Keyword(s):  
Enzyme Activity ◽  
Lead Nitrate ◽  
Initial Step ◽  
Lead Ions ◽  
Fixation Time ◽  
Animal Tissues ◽  
Root Tips ◽  
Cytochemical Localization ◽  
Onion Root ◽  
L1210 Cells

As the initial step toward the cytochemical localization of glycosyl-transferases in situ, biochemical determinations of these enzyme activities from onion root tips and L1210 cells were performed before and after fixation as well as in the presence of lead ions. Glycosyltransferase activity from roots fixed in buffered formaldehyde or glutaraldehyde before homogenization decreased as the concentration of the fixative or fixation time was increased. Formaldehyde fixation was less inhibitory than glutaraldehyde; 35% of the glycosyltransferase activity was retained after 30 min fixation in 2% formaldehyde while 25% of the enzyme activity remained after a similar fixation in glutaraldehyde. Substantially higher levels of L1210 cell glycosyltransferase activity were retained after a 30 min 2% formaldehyde fixation (60% sialyltransferase; 82% galactosyltransferase), but inhibition by glutaraldehyde was similar to that observed for onion root galactosyltransferase. Glycosyltransferase from formaldehyde-fixed roots was inhbited 35% by lead nitrate, but sialytransferase from formaldehyde-fixed L1210 cells was unaffected by lead ions. These findings are encouraging for further studies aimed at the development of cytochemical technique to localize glycosyltransferase in plant and animal tissues.

scholarly journals Amino acids important in enzyme activity and dimer stability for Drosophila alcohol dehydrogenase

1995 ◽  
Vol 308 (2) ◽  
pp. 419-423 ◽  
Author(s):  
S W Chenevert ◽  
N G Fossett ◽  
S H Chang ◽  
I Tsigelny ◽  
M E Baker ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Alcohol Dehydrogenase ◽  
Binding Site ◽  
Aspartic Acid ◽  
Three Dimensional ◽  
Side Chain ◽  
Wild Type ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Substrate Binding Site

We have determined the nucleotide sequences of eight ethyl methanesulphonate-induced mutants in Drosophila alcohol dehydrogenase (ADH), of which six were previously characterized by Hollocher and Place [(1988) Genetics 116, 253-263 and 265-274]. Four of these ADH mutants contain a single amino acid change: glycine-17 to arginine, glycine-93 to glutamic acid, alanine-159 to threonine, and glycine-184 to aspartic acid. Although these mutants are inactive, three mutants (Gly17Arg, Gly93Glu and Gly184Asp) form stable homodimers, as well as heterodimers with wild-type ADH, in which the wild-type ADH subunit retains full enzyme activity [Hollocher and Place (1988) Genetics 116, 265-274]. Interestingly, the Ala159Thr mutant does not form either stable homodimers or heterodimers with wild-type ADH, suggesting that alanine-159 is important in stabilizing ADH dimers. The mutations were analysed in terms of a three-dimensional model of ADH using bacterial 20 beta-hydroxysteroid dehydrogenase and rat dihydropteridine reductase as templates. The model indicates that mutations in glycine-17 and glycine-93 affect the binding of NAD+. It also shows that alanine-159 is part of a hydrophobic anchor on the dimer interface of ADH. Replacement of alanine-159 with threonine, which has a larger side chain and can hydrogen bond with water, is likely to reduce the strength of the hydrophobic interaction. The three-dimensional model shows that glycine-184 is close to the substrate binding site. Replacement of glycine-184 with aspartic acid is likely to alter the position of threonine-186, which we propose hydrogen bonds to the carboxamide moiety of NAD+. Also, the negative charge on the aspartic acid side chain may interact with the substrate and/or residues in the substrate binding site. These mutations provide information about ADH catalysis and the stability of dimers, which may also be useful in understanding homologous dehydrogenases, which include the human 17 beta-hydroxysteroid, 11 beta-hydroxysteroid and 15-hydroxyprostaglandin dehydrogenases.

Long-term dynamics of mycorrhizal root tips in a loblolly pine forest grown with free-air CO2enrichment and soil N fertilization for 6 years

2014 ◽  
Vol 20 (4) ◽  
pp. 1313-1326 ◽  
Author(s):  
Seth G. Pritchard ◽  
Benton N. Taylor ◽  
Emily R. Cooper ◽  
Katilyn V. Beidler ◽  
Allan E. Strand ◽  
...  
Keyword(s):  
Loblolly Pine ◽  
N Fertilization ◽  
Pine Forest ◽  
Soil N ◽  
Root Tips ◽  
Mycorrhizal Root ◽  
Free Air

scholarly journals Regulation of enzyme activities in Drosophila: I. The detection of regulatory loci by gene dosage responses

1974 ◽  
Vol 24 (1) ◽  
pp. 59-72 ◽  
Author(s):  
John M. Rawls ◽  
John C. Lucchesi
Keyword(s):  
Enzyme Activity ◽  
Drosophila Melanogaster ◽  
Alcohol Dehydrogenase ◽  
Gene Dosage ◽  
Regulatory Elements ◽  
Gpdh Activity ◽  
Regulatory Loci ◽  
Chromosome Ii ◽  
Chromosome Segments ◽  
Regulatory Sites

SUMMARYIn order to detect regulatory genetic sites in the autosomes of Drosophila melanogaster, the levels of X-linked glucose-6-phosphate dehydro-genase and autosomally linked α-glycerophosphate and isocitrate dehydrogenases have been monitored in extracts of flies aneuploid for regions of chromosomes II and III. In addition to expected structural gene dosage responses of α-GPDH and IDH, flies hyperploid for several autosome regions were found to display altered levels of one or more of the enzymes studied. While IDH activity was increased in flies hyperploid for segments of both chromosomes II and III, α-GPDH activity was decreased in specific hyperploids for chromosome II regions only. The latter group of segmental aneuploids were normal with respect to levels of chromosome II-linked alcohol dehydrogenase. To test if the observed responses were due to dosage changes of discrete genes lying within the larger effective segments, flies aneuploid for subdivisions of the chromosome segments 21A-25CD, 35A–40, and 70CD–71B were assayed. For two of these large segments so analysed, the apparent effects were attributable to specific small subdivisions, suggesting the presence of discrete regulatory sites within the latter. For the 35A–40 region the α-GPDH effect observed for subdivisions was not sufficient to account for the large α-GPDH decrease seen in flies hyperploid for the large, inclusive region. These observations are discussed with respect to the possible bases of effect of regulatory elements on enzyme activity.

Somatic polyembryogenesis in embryogenic cell masses of Piceaabies (Norway spruce) and Pinustaeda (loblolly pine) after thawing from liquid nitrogen

1987 ◽  
Vol 17 (9) ◽  
pp. 1130-1134 ◽  
Author(s):  
P. K. Gupta ◽  
D. J. Durzan ◽  
B.J. Finkle
Keyword(s):  
Liquid Nitrogen ◽  
Loblolly Pine ◽  
Somatic Embryos ◽  
Cell Mass ◽  
Embryogenic Cell ◽  
Long Term Storage ◽  
Embryogenic Cell Lines ◽  
Improvement Programs ◽  
Term Storage

We describe a method for the possible cryopreservation of embryogenic callus of Piceaabies and Pinustaeda at −196 °C and the regeneration of somatic embryos from thawed cells of subcultured embryonal–suspensor masses. Piceaabies and Pinustaeda were frozen without cryoprotective agent, in the presence of dimethyl sulfoxide (10%), or in a mixture of polyethylene glycol, glucose, and dimethylsulfoxide (10, 8, and 10% w/v, respectively). Cell masses placed in plastic vials or aluminum envelopes were frozen at 1 °C/min to −30 °C and then immersed for 10 min in liquid nitrogen. Cells were thawed rapidly and placed on modified MS subculture medium. Six to seven somatic embryos per gram of fresh weight were regenerated from each piece of frozen cell mass as compared with 12–13 embryos per gram from unfrozen cells. Post-thaw cell growth was inhibited initially by up to 5 weeks. Inhibition was reversed after the third 10-day subculture. Results suggest that the long-term storage of embryogenic cell lines in liquid nitrogen may be feasible for tree improvement programs in circumstances where testing of progeny may take several years.

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