enzymatic transformation
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2021 ◽  
Vol 23 (1) ◽  
pp. 285
Author(s):  
Victor V. Dyakin ◽  
Nuka V. Dyakina-Fagnano ◽  
Laura B. Mcintire ◽  
Vladimir N. Uversky

In humans, age-associated degrading changes, widely observed in molecular and cellular processes underly the time-dependent decline in spatial navigation, time perception, cognitive and psychological abilities, and memory. Cross-talk of biological, cognitive, and psychological clocks provides an integrative contribution to healthy and advanced aging. At the molecular level, genome, proteome, and lipidome instability are widely recognized as the primary causal factors in aging. We narrow attention to the roles of protein aging linked to prevalent amino acids chirality, enzymatic and spontaneous (non-enzymatic) post-translational modifications (PTMs SP), and non-equilibrium phase transitions. The homochirality of protein synthesis, resulting in the steady-state non-equilibrium condition of protein structure, makes them prone to multiple types of enzymatic and spontaneous PTMs, including racemization and isomerization. Spontaneous racemization leads to the loss of the balanced prevalent chirality. Advanced biological aging related to irreversible PTMs SP has been associated with the nontrivial interplay between somatic (molecular aging) and mental (psychological aging) health conditions. Through stress response systems (SRS), the environmental and psychological stressors contribute to the age-associated “collapse” of protein homochirality. The role of prevalent protein chirality and entropy of protein folding in biological aging is mainly overlooked. In a more generalized context, the time-dependent shift from enzymatic to the non-enzymatic transformation of biochirality might represent an important and yet underappreciated hallmark of aging. We provide the experimental arguments in support of the racemization theory of aging.


Author(s):  
Victor Vasilyevich Dyakin ◽  
Nika Victorovna Dyakina-Fagnano ◽  
Laura Beth McIntire ◽  
Vladimir Nikolaevich Uversky

In humans, age-associated degrading changes are observed in molecular and cellular processes underly the time-dependent decline in spatial navigation, time perception, cognitive and psy-chological abilities, and memory. Cross talk of biological, cognitive, and psychological clocks provides an integrative contribution to healthy and advanced aging. At the molecular level, ge-nome, proteome, and lipidome instability are widely recognized as the primary causal factors in aging. We narrow attention to the roles of protein aging linked to prevalent amino acids chirali-ty, enzymatic and spontaneous (non-enzymatic) post-translational modifications (PTMs SP), and non-equilibrium phase transitions. The homochirality of protein synthesis, resulting in the steady-state non-equilibrium condition of protein structure, makes them prone to multiple types of enzymatic and spontaneous PTMs, including racemization and isomerization. Spontaneous racemization leads to the loss of the balanced prevalent chirality. Advanced biological aging re-lated to irreversible PTMs SP has been associated with the nontrivial interplay between poor so-matic and mental health conditions. Through stress response systems (SRS), the environmental and psychological stressors contribute to the age-associated “collapse” of protein homochirality. The role of prevalent protein chirality and entropy of protein folding in biological aging is mainly overlooked. In a more generalized context, the time-dependent shift from enzymatic to the non-enzymatic transformation of biochirality might represent an important and yet un-der-appreciated hallmark of aging.


2021 ◽  
Author(s):  
Carlos Alonso-Alvarez ◽  
Pedro Andrade ◽  
Alejandro Cantarero ◽  
Miguel Carneiro

Sexual and social selections promote the evolution of many conspicuous colorations in animals. These traits would act as individual quality signals when they transmit reliable information. Reliability should be assured by production costs unaffordable for low-quality trait bearers or guaranteed if trait expression is tightly linked to individual quality and cannot be falsified (“index signals”). It has been suggested that colored ornaments produced by red ketocarotenoid pigments could meet the latter. These ketocarotenoids are often obtained by enzymatic transformation of dietary yellow carotenoids. Recently, the first enzyme performing this transformation has been described: CYP2J19. This enzyme, belonging to the cytochrome p450 superfamily, is presumably located in the inner mitochondrial membrane, thus linking color expression with cell respiration efficacy. However, it remains to be clarified if the tissue where this intracellular mechanism acts could influence signal reliability and trait evolution. CYP2J19 expression data are now available for different species and tissues. Here, we review current data in birds and hypothesize that CYP2J19 activity could have evolved in some species by being relocated from the liver tissue to the ornaments (epidermis), a pattern more strongly observed in those birds where the red is expressed in non-feathered bare parts (e.g. bill, legs). One potential explanation is that bare parts, unlike feathers, require a constant carotenoid mobilization to maintain color throughout the year. We propose that tissue relocation allows for avoiding production costs derived from potential CYP2J19 interference on vital liver functions. Implications for signal reliability in ornamental evolution are discussed.


Author(s):  
Gyeong Han Jeong ◽  
Jae-Hyeon Cho ◽  
Eui Kyun Park ◽  
Tae Hoon Kim

Abstract Enzymatic structure modification of the representative chalcone phloretin (1) with polyphenol oxidase from Agaricus bisporus origin produced two new biphenyl-type phloreoxin (2) and phloreoxinone (3), and a previously undescribed (2R)-5,7,3“,5”-tetrahydroxyflavanone (4). The structure of these new oxidized products 2‒4 elucidated by interpreting the spectroscopic data (NMR and FABMS) containing the absolute stereochemistry established by analysis of the circular dichroism (CD) spectrum. Compared to the original phloretin, the new products (2) and (3) showed highly improved anti-adipogenic potencies both toward pancreatic lipase and accumulation of 3T3-L1 cells. Aslo, phloreoxin (2) effectively inhibited the expression of C/EBPβ, PPARγ, and aP2 at the mRNA level in the 3T3 adipocytes. Thus, phloreoxin (2), containing a biphenyl moiety catalyzed by A. bisporus polyphenol oxidase, have the potential to influence the anti-adipogenic capacity.


2021 ◽  
pp. 20-22
Author(s):  
Ирина Сергеевна Витол ◽  
Елена Павловна Мелешкина

Показана эффективность действия ферментных препаратов (ФП) целлюлолитического и протеолитического действия отечественного и зарубежного производства и мультиэнзимных композиций (МЭК) на их основе на биополимеры пшенично-льняных отрубей. The efficiency of the action of enzyme preparations (FP) of cellulolytic and proteolytic action of domestic and foreign production and multi-enzyme compositions (MEС) based on them on biopolymers of wheat-flax bran.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yuanyuan Yao ◽  
Xian Shu ◽  
Dongdong Wang ◽  
Wenjie Kan ◽  
Pengfei Su ◽  
...  

Aflatoxin B1 (AFB1) is the most harmful mycotoxin produced by filamentous fungi and presents a serious threat to human and animal health. Therefore, it is essential to protect humans and animals from AFB1-induced acute and chronic toxicity. In this study, Pseudomonas strain m29 having a high efficiency of AFB1 transformation was isolated from soil. The transformation ratio by m29 was more than 97% within 24 h, and the optimum temperature for transformation was 37°C. Moreover, the AFB1 transforming activity was mainly attributed to the cell-free supernatant of strain m29. The metabolite that plays a crucial role in AFB1 transformation is likely 1,2-dimethylhydrazine or 1,1-dimethylhydrazine, as identified by GC-MS and LC-MS analysis. AFB1 was transformed into a product with molecular formula C17H14O7. To the best of our knowledge, this is the first study of non-enzymatic AFB1 transformation by bacteria. Importantly, this AFB1 transformation mechanism could be universal to various microorganisms.


2021 ◽  
pp. 254-261
Author(s):  
Vladimir Kondratenko ◽  
Tatyana Kondratenko ◽  
Andrey Petrov

Introduction. The functional basis of protopectin complex can be represented as a network of regions that consist of homogalacturonan sequences and a base of rhamnogalacturonans-I, i.e. rhamnosyl-containing branching sites. Enzymatic isolation of these regions is possible only at a certain minimal native degree of polymerization. The research objective was to develop a system of criteria for assessing the potential applicability of the enzymatic transformation of plant protopectin complex. Study objects and methods. The research featured the polymerization degree of the homogalacturonan regions of the protopectin complex and produced a system of assessment criteria for the enzymatic fragmentation potential of the protopectin complex. The theoretical calculations were based on the values of the mass fractions of rhamnosyl and galacturonide residues in plant cell walls. The result was a new polymerization degree analytical function. Results and discussion. The ratio of the mass fractions of rhamnosyl and galacturonide residues in the water-insoluble plant tissue served as a dimensionless criterion of applicability. The rational condition for the dimensionless criterion of applicability was based on the fundamental constraint for homogalacturonan regions in the protopectin complex. It was expressed by a fundamental inequation. The rational area for determining the numerical values of the applicability criterion was presented as . The functional dependence was reduced to a two-dimensional criteria space as “width of rhamnosyl branches vs. the criterion of applicability”, where each pectin-containing raw material was given a single uniquely defined position. The boundary conditions for the criteria space were determined analytically. Conclusion. The new approach offers an assessment of the enzymatic fragmentation potential of the plant protopectin complex by homoenzyme preparations. The approach is in fact the second stage of the decision tree in the science-based technology for pectin and its products.


Biomass ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 29-59
Author(s):  
Enrico Scelsi ◽  
Antonella Angelini ◽  
Carlo Pastore

The growing demand for energy and materials in modern society pushes scientific research to finding new alternative sources to traditional fossil feedstocks. The exploitation of biomass promises to be among the viable alternatives with a lower environmental impact. Making biomass exploitation technologies applicable at an industrial level represents one of the main goals for our society. In this work, the most recent scientific studies concerning the enhancement of lignocellulosic biomasses through the use of deep eutectic solvent (DES) systems have been examined and reported. DESs have an excellent potential for the fractionation of lignocellulosic biomass: the high H-bond capacity and polarity allow the lignin to be deconvolved, making it easier to break down the lignocellulosic complex, producing a free crystallite of cellulose capable of being exploited and valorised. DESs offer valid alternatives of using the potential of lignin (producing aromatics), hemicellulose (achieving furfural) and cellulose (delivering freely degradable substrates through enzymatic transformation into glucose). In this review, the mechanism of DES in the fractionation of lignocellulosic biomass and the main possible uses for the valorisation of lignin, hemicellulose and cellulose were reported, with a critical discussion of the perspectives and limits for industrial application.


Author(s):  
Lingling Zhao ◽  
Zhenyang Zhao ◽  
Kaiyun Zhang ◽  
Xuan Zhang ◽  
Siqiong Xu ◽  
...  

Cotinine is a stable toxic contaminant, produced as a byproduct of smoking. It is of emerging concern due to its global distribution in aquatic environments. Microorganisms have the potential to degrade cotinine, however, the genetic mechanisms of this process are unknown. Nocardioides sp. strain JQ2195 is a pure culture strain that has been reported to degrade cotinine at micropollutant concentrations. This strain utilizes cotinine as its sole carbon and nitrogen source. In this study, a 50 kb gene cluster (designated as cot ) involved in cotinine degradation, was predicted based on genomic and transcriptomic analyses. A novel three-component cotinine hydroxylase gene (designated as cotA1A2A3 ), which initiated cotinine catabolism was identified and characterized. CotA from Shinella sp. HZN7 was heterologously expressed and purified, and shown to convert cotinine into 6-hydroxycotinine. H 2 18 O-labelling and ESI-MS analysis confirmed that the hydroxyl group incorporated into 6-hydroxycotinine was derived from water. This study provides new molecular insights into the microbial metabolism of heterocyclic chemical pollutants. IMPORTANCE In the human body, cotinine is the major metabolite of nicotine, and 10–15% of generated cotinine is excreted in urine. Cotinine is a structural analogue of nicotine and is much more stable than nicotine. Increased tobacco consumption has led to high environmental concentrations of cotinine, which may have detrimental effects on aquatic ecosystems and human health. Nocardioides sp. strain JQ2195 is a unique cotinine-degrading bacterium. However, the underlying genetic and biochemical foundations of cotinine degradation are still unknown. In this study, a 50 kb gene cluster (designated cot ) was identified by genomic and transcriptomic analyses as being involved in the degradation of cotinine. A novel three-component cotinine hydroxylase gene (designated cotA1A2A3 ) catalyzed cotinine to 6-hydroxy-cotinine. This study provides new molecular insights into the microbial degradation and enzymatic transformation of cotinine.


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