A FLUOROMETRIC ASSAY FOR PROTEINASE A IN BEER AND ITS APPLICATION FOR THE INVESTIGATION OF ENZYMATIC EFFECTS ON FOAM STABILITY

Vacuolar proteinase A (Pep4p) is required for the post-translational precursor maturation of vacuolar proteinases in Saccharomyces cerevisiae, and important for protein turnover after oxidative damage. The presence of proteinase A in brewing yeast leads to the decline of beer foam stability, thus the deletion or inhibition of Pep4p is generally used. However, the influence of Pep4p deletion on cell metabolism in Saccharomyces cerevisiae is still unclear. Herein, we report the identification of differentially down-regulated metabolic proteins in the absence of Pep4p by a comparative proteomics approach. 2D-PAGE (two-dimensional polyacrylamide gel electrophoresis) presented that the number of significantly up-regulated spots (the Pep4p-deficient species versus the wild type) was 183, whereas the down-regulated spots numbered 111. Among them, 35 identified proteins were differentially down-regulated more than 10-fold in the Pep4p-deficient compared to the wild-type species. The data revealed that Pep4p was required for the synthesis and maturation of several glycolytic enzymes and stress proteins, including Eno2p, Fba1p, Pdc1p, Tpi1p, Ssa1, Hsp82p, and Trr1p. The transcription and post-translational modifications of glycolytic enzymes like Eno2p and Fba1p were sensitive to the absence of Pep4p; whereas the depletion of the pep4 gene had a negative impact on mitochondrial and other physiological functions. The finding of this study provides a systematic understanding that Pep4p may serve as a regulating factor for cell physiology and metabolic processes in S. cerevisiae under a nitrogen stress environment.

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Purification and fluorometric assay of proteinase A from yeast

Analytical Biochemistry ◽

10.1016/0003-2697(83)90286-5 ◽

1983 ◽

Vol 134 (1) ◽

pp. 210-215 ◽

Cited By ~ 18

Author(s):

Hideyoshi Yokosawa ◽

Hiroshi Ito ◽

Shigeki Murata ◽

Shin-ichi Ishii

Keyword(s):

Fluorometric Assay ◽

Proteinase A

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The primary structure of Aspergillus niger acid proteinase A.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)55021-3 ◽

1991 ◽

Vol 266 (29) ◽

pp. 19480-19483 ◽

Cited By ~ 1

Author(s):

K. Takahashi ◽

H. Inoue ◽

K. Sakai ◽

T. Kohama ◽

S. Kitahara ◽

...

Keyword(s):

Aspergillus Niger ◽

Primary Structure ◽

Acid Proteinase ◽

Proteinase A

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A fluorometric assay for α-glucosidase activity based on quaternary AgInZnS QDs

Microchimica Acta ◽

10.1007/s00604-021-04855-5 ◽

2021 ◽

Vol 188 (7) ◽

Author(s):

Jiabao Zhang ◽

Jinying Liu ◽

Mengke Wang ◽

Guannan Wang ◽

Xingguang Su

Keyword(s):

Fluorometric Assay ◽

Glucosidase Activity

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Novel asymmetrical bis-surfactants with naphthalene and two amide groups: Synthesis, foamability and foam stability

Journal of Molecular Liquids ◽

10.1016/j.molliq.2021.115534 ◽

2021 ◽

Vol 329 ◽

pp. 115534

Author(s):

Yue Jia ◽

Xiangfeng Guo ◽

Lihua Jia ◽

Zhenlong Zhao ◽

Rui Yang ◽

...

Keyword(s):

Foam Stability

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Impact of tailored water chemistry aqueous ions on foam stability enhancement

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01216-z ◽

2021 ◽

Author(s):

Zuhair AlYousef ◽

Subhash Ayirala ◽

Majed Almubarak ◽

Dongkyu Cha

Keyword(s):

Aqueous Solutions ◽

Water Chemistry ◽

Foam Stability ◽

Chloride Salt ◽

Foam Generation ◽

Monovalent Ions ◽

Injection Water ◽

Foam Stabilization ◽

Aqueous Ions ◽

The Impact

AbstractGenerating strong and stable foam is necessary to achieve in-depth conformance control in the reservoir. Besides other parameters, the chemistry of injection water can significantly impact foam generation and stabilization. The tailored water chemistry was found to have good potential to improve foam stability. The objective of this study is to extensively evaluate the effect of different aqueous ions in the selected tailored water chemistry formulations on foam stabilization. Bulk and dynamic foam experiments were used to evaluate the impact of different tailored water chemistry aqueous ions on foam generation and stabilization. For bulk foam tests, the stability of foams generated using three surfactants and different aqueous ions was analyzed using bottle tests. For dynamic foam experiments, the tests were conducted using a microfluidic device. The results clearly demonstrated that the ionic content of aqueous solutions can significantly affect foam stabilization. The results revealed that the foam stabilization in bulk is different than that in porous media. Depending on the surfactant type, the divalent ions were found to have stronger influence on foam stabilization when compared to monovalent ions. The bulk foam results pointed out that the aqueous solutions containing calcium chloride salt (CaCl2) showed longer foam life with the anionic surfactant and very weak foam with the nonionic surfactant. The solutions with magnesium chloride (MgCl2) and CaCl2 salts displayed higher impact on foam stability in comparison with sodium chloride (NaCl) with the amphoteric alkyl amine surfactant. Less stable foams were generated with aqueous solutions comprising of both magnesium and calcium ions. In the microfluidic model, the solutions containing MgCl2 showed higher resistance to gas flow and subsequently higher mobility reduction factor for the injection gas when compared to those produced using NaCl and CaCl2 salts. This experimental study focusing about the role of different aqueous ions in the injection water on foam could help in better understanding the foam stabilization process. The new knowledge gained can also enable the selection and optimization of the right injection water chemistry and suitable chemicals for foam field applications.

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Correlations between the Type of Aggregates in the Bulk Phase and the Functionality and Safety of All-Purpose Cleaners

International Journal of Molecular Sciences ◽

10.3390/ijms22126592 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6592

Author(s):

Artur Seweryn ◽

Tomasz Wasilewski ◽

Anita Bocho-Janiszewska

Keyword(s):

Sodium Chloride ◽

Magnesium Chloride ◽

Foam Stability ◽

Bulk Phase ◽

Magnesium Salt ◽

Foaming Properties ◽

Performance Properties ◽

Salt Addition ◽

And Performance ◽

The Given

The article shows that the type and concentration of inorganic salt can be translated into the structure of the bulk phase and the performance properties of ecological all-purpose cleaners (APC). A base APC formulation was developed. Thereafter, two types of salt (sodium chloride and magnesium chloride) were added at various concentrations to obtain different structures in the bulk phase. The salt addition resulted in the formation of spherical micelles and—upon addition of more electrolyte—of aggregates having a lamellar structure. The formulations had constant viscosities (ab. 500 mPa·s), comparable to those of commercial products. Essential physical-chemical and performance properties of the four formulations varying in salt types and concentrations were evaluated. It was found that the addition of magnesium salt resulted in more favorable characteristics due to the surface activity of the formulations, which translated into adequately high wettability of the investigated hydrophobic surfaces, and their ability to emulsify fat. A decreasing relationship was observed in foaming properties: higher salt concentrations lead to worse foaming properties and foam stability of the solutions. For the magnesium chloride composition, the effect was significantly more pronounced, as compared to the sodium chloride-based formulations. As far as safety of use is concerned, the formulations in which magnesium salt was used caused a much lesser irritation compared with the other investigated formulations. The zein value was observed to decrease with increasing concentrations of the given type of salt in the composition.

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