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 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 Kinetic and Isotherm Studies of Sewage Sludge Biochar on Ammonium Solution

2020 ◽  
Author(s):  
Khairunissa Syairah Ahmad Sohaimi ◽  
Ong Chyh Shyang ◽  
Nur Izzati Iberahim ◽  
Alina Rahayu Mohamed ◽  
Noor Ainee Zainol
Keyword(s):  
Sewage Sludge ◽  
Point Charge ◽  
Chemical Properties ◽  
Zero Point ◽  
Ash Content ◽  
Ammonium Adsorption ◽  
Optimum Ph ◽  
Charge Analysis ◽  
Physical And Chemical ◽  
And Chemical Properties

Sewage sludge was utilized into biochar using the slow pyrolysis method. The biochar was then being used for ammonium removal. The sewage sludge biochar was produced at temperature of 550°C, 600°C, 650°C, 700°C and 750°C. A few characterization tests were carried out to study about the physical and chemical properties of the biochar. For instance, moisture and ash content analysis, FTIR spectroscopy, pH Zero Point Charge, biochar yield and SEM. As the pyrolysis temperature increased, the moisture content of SSB decreased while the ash content increased. The FTIR spectra of sewage sludge biochar showed that there were various organic functional groups on the surface of the biochar which were responsible for ammonium adsorption. Furthermore, through pH Zero Point Charge analysis, pH 7.0 was the most optimum pH for the adsorption test of ammonium. The optimum adsorbent dosage was 0.01g while optimum contact time was 150 minutes. Furthermore, 1.2ppm was the most optimum concentration for adsorption process. Based on the result of the characterization tests, SSB700 was the most effective biochar for ammonium adsorption. Based on the result of kinetic and isotherm analysis, the adsorption of ammonium ions usign sewage sludge biochar was a monolayer chemisorption process.

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.

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 Kinetic and Isotherm Studies Biochar on Ammonium Solution

2020 ◽  
Author(s):  
Khairunissa Syairah Ahmad Sohaimi ◽  
Ong Chyh Shyang ◽  
Nur Izzati Iberahim ◽  
Alina Rahayu Mohamed
Keyword(s):  
Sewage Sludge ◽  
Point Charge ◽  
Chemical Properties ◽  
Zero Point ◽  
Ash Content ◽  
Ammonium Adsorption ◽  
Optimum Ph ◽  
Charge Analysis ◽  
Physical And Chemical ◽  
And Chemical Properties

Sewage sludge was utilized into biochar using the slow pyrolysis method. The biochar was then being used for ammonium removal. The sewage sludge biochar was produced at temperature of 550°C, 600°C, 650°C, 700°C and 750°C. A few characterization tests were carried out to study about the physical and chemical properties of the biochar. For instance, moisture and ash content analysis, FTIR spectroscopy, pH Zero Point Charge, biochar yield and SEM. As the pyrolysis temperature increased, the moisture content of SSB decreased while the ash content increased. The FTIR spectra of sewage sludge biochar showed that there were various organic functional groups on the surface of the biochar which were responsible for ammonium adsorption. Furthermore, through pH Zero Point Charge analysis, pH 7.0 was the most optimum pH for the adsorption test of ammonium. The optimum adsorbent dosage was 0.01g while optimum contact time was 150 minutes. Furthermore, 1.2ppm was the most optimum concentration for adsorption process. Based on the result of the characterization tests, SSB700 was the most effective biochar for ammonium adsorption. Based on the result of kinetic and isotherm analysis, the adsorption of ammonium ions usign sewage sludge biochar was a monolayer chemisorption process.

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.

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