Composition of DNA from Phytophthora infestans

1968 ◽  
Vol 14 (4) ◽  
pp. 482-483 ◽  
Author(s):  
M. C. Clark ◽  
C. H. Lawrence ◽  
O. T. Page ◽  
W. A. Hodgson
Keyword(s):  
Phytophthora Infestans ◽  
Thermal Denaturation ◽  
Deoxyribonucleic Acid ◽  
Dna Analysis ◽  
Chemical Properties ◽  
Electrophoretic Analysis ◽  
Nucleotide Composition ◽  
Physical And Chemical ◽  
Hydrolysis Of ◽  
And Chemical Properties

Deoxyribonucleic acid was extracted from the late blight fungus, Phytophthora infestans, and partially characterized in terms of its physical and chemical properties. Hydrolysis of the purified DNA followed by electrophoretic analysis failed to demonstrate the presence of constituents other than those characteristically found in DNA. Analysis of the nucleotide composition based on thermal denaturation studies yielded values for the percentage guanine–cytosine which are consistent with those reported for other members of the Phycomycetes.

scholarly journals Polar Head Modified Phospholipids by Phospholipase D-Catalyzed Transformations of Natural Phosphatidylcholine for Targeted Applications: An Overview

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 997
Author(s):  
Chiara Allegretti ◽  
Francesca Denuccio ◽  
Letizia Rossato ◽  
Paola D’Arrigo
Keyword(s):  
Phospholipase D ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Reaction Conditions ◽  
Chemical Methods ◽  
Polar Head ◽  
Transphosphatidylation Reaction ◽  
Physical And Chemical ◽  
Hydrolysis Of ◽  
And Chemical Properties

This review describes the use of phospholipase D (PLD) to perform the transphosphatidylation of the most common natural phospholipid (PL), phosphatidylcholine (PC) to obtain polar head modified phospholipids with real targeted applications. The introduction of different polar heads with distinctive physical and chemical properties such as charge, polarity and dimensions allows the obtainment of very different PLs, which can be exploited in very diverse fields of application. Moreover, the inclusions of a bioactive moiety in the PL polar head constitutes a powerful tool for the stabilization and administration of active ingredients. The use of this biocatalytic approach allows the preparation of compounds which cannot be easily obtained by classical chemical methods, by using mild and green reaction conditions. PLD is a very versatile enzyme, able to catalyze both the hydrolysis of PC to choline and phosphatidic acid (PA), and the transphosphatidylation reaction in the presence of an appropriate alcohol. The yield of production of the desired product and the ratio with the collateral PA formation is highly dependent on parameters such as the nature and concentration of the alcohol and the enzymatic source. The application of PLD catalyzed transformations for the production of a great number of PLs with important uses in medical, nutraceutical and cosmetic sectors will be discussed in this work.

THE EFFECT OF GLUCOAMYLASE ON VARIOUS TYPES OF STARCH IN THE NATIVE STATE

2020 ◽  
pp. 284-285
Author(s):  
Z. Borodina
Keyword(s):  
Low Temperature ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Native State ◽  
Physical And Chemical ◽  
Hydrolysis Of ◽  
And Chemical Properties

Was conducted a study of low-temperature hydrolysis of various types of starch in the native state: corn, corn amylopectin, pea, wheat and rice starches. Were establidhed different susceptibility of starches to the action of the enzyme glucoamylase, changes in the physical and chemical properties of samples after hydrolysis.

Pyridoxal phosphate as a constituent of the histaminase (benzylamine oxidase) of pig plasma

1965 ◽  
Vol 163 (990) ◽  
pp. 45-60 ◽  
Keyword(s):  
Acid Hydrolysis ◽  
Pyridoxal Phosphate ◽  
Phosphorus Content ◽  
Chemical Properties ◽  
Subsequent Treatment ◽  
Fluorescence Properties ◽  
Benzylamine Oxidase ◽  
Physical And Chemical ◽  
Hydrolysis Of ◽  
And Chemical Properties

The histaminase (‘benzylamine oxidase’) of pig plasma has recently been crystallized and a description is given of some of the physical and chemical properties of the pure preparation of the oxidase. The fluorescence of the enzyme is typical of a protein containing tryptophan. The phosphorus content is about four atoms per molecule. On enzymic hydrolysis a product has been obtained that has the fluorescence properties of a pyridoxal protein. This product gave rise on acid hydrolysis to material capable of activating the L-tyrosine apodecarboxylase of Streptococcus faecalis R in the presence of adenosine triphosphate, indicating that pyridoxal was set free in the hydrolysis. Acid hydrolysis of a solution of the crystalline enzyme and subsequent treatment with urea yielded diffusible material with the spectroscopic and fluorescence properties of pyridoxal. Using the bacterial apodecarboxylase, traces of pyridoxal phosphate and larger amounts of free pyridoxal were shown to be present. It was calculated that about 3 or 4 moles of pyridoxal were present per mole of enzyme. Together with the phosphate estimations, these observations lead to the conclusion that the oxidase contains 3 or 4 moles of pyridoxal phosphate per mole. Observations on rats maintained on a diet deficient in vitamin B 6 are in agreement with these conclusions.

scholarly journals β-amylase-resistant amylose. Effect of urea on the limited hydrolysis of amylose by β-amylase

1976 ◽  
Vol 153 (2) ◽  
pp. 339-342 ◽  
Author(s):  
N B Patil
Keyword(s):  
Active Site ◽  
Chemical Properties ◽  
Inhibitory Effect ◽  
Physical And Chemical Properties ◽  
Urea Treatment ◽  
Conventional Methods ◽  
Physical And Chemical ◽  
Hydrolysis Of ◽  
And Chemical Properties

Amylose prepared from starch dispersed in 10M-urea, pH6.2, was found to be resistant to the action of β-amylase and phosphorylase, though it was degraded by α-amylase. Amylose isolated by conventional methods was similarly refractory after urea treatment, and was hydrolysed by β-amylase to the extent of 32-35%; it had no inhibitory effect towards β-amylase. The physical and chemical properties of the modified amylose were in general comparable with those of normal amylose with a β-amylolysis limit of 94-98%%. Starch and amylopectin were unaffected by urea treatment, i.e. the presence of amylopectin protected amylose against changes induced in it by urea. It is speculated that urea treatment “freezes” amylose molecules in a conformation that renders non-reducing termini inaccessible to the active site of the exo-enzymes. Such changes may limit the degradative action of β-amylase and phosphorylase.

scholarly journals Bioenergy Conversion Potential of Decaying Hardwoods

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 93
Author(s):  
Éloïse Dupuis ◽  
Evelyne Thiffault ◽  
Julie Barrette ◽  
Kokou Adjallé ◽  
Christine Martineau
Keyword(s):  
Relative Abundance ◽  
Dna Analysis ◽  
Chemical Properties ◽  
Specific Effect ◽  
White Rot Fungi ◽  
White Rot ◽  
Physical And Chemical Properties ◽  
Bioenergy Production ◽  
Physical And Chemical ◽  
And Chemical Properties

Unharvested hardwoods are abundant in eastern Canada, due to the low quality of their fiber and the absence of outlets in conventional wood transformation industries. The objective of this study was to assess the biochemical and thermochemical energy conversion potential of decaying hardwoods and compare their relationships with external and internal indicators of tree degradation. We characterized how wood-decay processes altered the physical and chemical properties of these woods and affected their digestibility yield and their performance according to indexes of stability and efficiency of combustion. DNA analysis on wood samples was also performed to determine the relative abundance of white-rot fungi compared to that of other saprotrophs. All properties stayed within the range of variations allowing the wood to remain suitable for conversion into bioenergy, even with increased decay. We found no significant differences in the physical and chemical properties that are crucial for energy production between wood from externally-assessed live and decayed trees. However, the proportion of wood area affected by rot was significantly associated with increased digestibility yield, and with decreased combustion reactivity. We could not detect any specific effect associated with increased relative abundance of white-rot fungi. These results suggest that the utilization of biomass from decayed hardwoods instead of live trees for bioenergy production should not alter the conversion efficiency and even potentially increase the performance of biochemical pathways, and hence, support their use as feedstock for bioenergy production.

scholarly journals CRYSTALLINE CHYMO-TRYPSIN AND CHYMO-TRYPSINOGEN

1935 ◽  
Vol 18 (4) ◽  
pp. 433-458 ◽  
Author(s):  
M. Kunitz ◽  
John H. Northrop
Keyword(s):  
Chemical Properties ◽  
Intramolecular Rearrangement ◽  
Milk Clotting ◽  
Optimum Ph ◽  
Primary Amino ◽  
Clot Blood ◽  
Physical And Chemical ◽  
Hydrolysis Of ◽  
Rate Of Activation ◽  
And Chemical Properties

A new crystalline protein, chymo-trypsinogen, has been isolated from acid extracts of fresh cattle pancreas. This protein is not an enzyme but is transformed by minute amounts of trypsin into an active proteolytic enzyme called chymo-trypsin. The chymo-trypsin has also been obtained in crystalline form. The chymo-trypsinogen cannot be activated by enterokinase, pepsin, inactive trypsin, or calcium chloride. There is an extremely slow spontaneous activation upon standing in solution. The activation of chymo-trypsinogen by trypsin follows the course of a monomolecular reaction the velocity constant of which is proportional to the trypsin concentration and independent of the chymotrypsinogen concentration. The rate of activation is a maximum at pH 7.0–8.0. Activation is accompanied by an increase of six primary amino groups per mole but no split products could be found, indicating that the activation consists in an intramolecular rearrangement. There is a slight change in optical activity but no change in molecular weight. The physical and chemical properties of both proteins are constant through a series of fractional crystallizations. The activity of chymo-trypsin decreases in proportion to the destruction of the native protein by pepsin digestion or denaturation by heat or acid. Chymo-trypsin has powerful milk-clotting power but does not clot blood plasma and differs qualitatively in this respect from the crystalline trypsin previously reported. It hydrolyzes sturin, casein, gelatin, and hemoglobin more slowly than does crystalline trypsin but the hydrolysis of casein is carried much further. The hydrolysis takes place at different linkages from those attacked by trypsin. The optimum pH for the digestion of casein is about 8.0–9.0. It does not hydrolyze any of a series of dipeptides or polypeptides tested. Several chemical and physical properties of both proteins have been determined.

scholarly journals pH dependence of C·A, G·A and A·A mismatches in the stem of precursor microRNA-31

2021 ◽  
Author(s):  
Anita Kotar ◽  
Sicong Ma ◽  
Sarah C Keane
Keyword(s):  
Base Pair ◽  
Thermal Denaturation ◽  
Ph Dependence ◽  
Chemical Properties ◽  
Mature Mirnas ◽  
Solution Ph ◽  
Physical And Chemical ◽  
Processing Steps ◽  
And Chemical Properties

MicroRNAs (miRNAs) are important regulators of post-transcriptional gene expression. Mature miRNAs are generated from longer transcripts (primary, pri- and precursor, pre-miRNAs) through a series of highly coordinated enzymatic processing steps. The sequence and structure of these pri- and pre-miRNAs play important roles in controlling their processing. Both pri- and pre-miRNAs adopt hairpin structures with imperfect base pairing in the helical stem. Here, we investigated the role of three base pair mismatches (A·A, G·A, and C·A) present in pre-miRNA-31. Using a combination of NMR spectroscopy and thermal denaturation, we found that the three base pair mismatches displayed unique structural properties, including varying dynamics and sensitivity to solution pH. These studies deepen our understanding of how the physical and chemical properties of base pair mismatches influence RNA structural stability.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Sign in / Sign up

Export Citation Format

Share Document