scholarly journals Post translational modifications of milk proteins in geographically diverse goat breeds

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
P. K. Rout ◽  
M. Verma

AbstractGoat milk is a source of nutrition in difficult areas and has lesser allerginicity than cow milk. It is leading in the area for nutraceutical formulation and drug development using goat mammary gland as a bioreactor. Post translational modifications of a protein regulate protein function, biological activity, stabilization and interactions. The protein variants of goat milk from 10 breeds were studied for the post translational modifications by combining highly sensitive 2DE and Q-Exactive LC-MS/MS. Here we observed high levels of post translational modifications in 201 peptides of 120 goat milk proteins. The phosphosites observed for CSN2, CSN1S1, CSN1S2, CSN3 were 11P, 13P, 17P and 6P, respectively in 105 casein phosphopeptides. Whey proteins BLG and LALBA showed 19 and 4 phosphosites respectively. Post translational modification was observed in 45 low abundant non-casein milk proteins mainly associated with signal transduction, immune system, developmental biology and metabolism pathways. Pasp is reported for the first time in 47 sites. The rare conserved peptide sequence of (SSSEE) was observed in αS1 and αS2 casein. The functional roles of identified phosphopeptides included anti-microbial, DPP-IV inhibitory, anti-inflammatory and ACE inhibitory. This is first report from tropics, investigating post translational modifications in casein and non-casein goat milk proteins and studies their interactions.

Author(s):  
ALESSA SIQUEIRA DE O. DOS SANTOS ◽  
VANEIDA MARIA MEURER ◽  
FABIANO FREIRE COSTA ◽  
IGOR MOURA DE PAIVA ◽  
GISELE NOGUEIRA FOGAÇA ◽  
...  

This work presents the electrophoretic profile of goat and cow milk samples and their mixtures using microfluidic and conventional electrophoresis. The microfluidic method allowed the separation of the major caseins from milk, excepting the goat κ-casein.  Besides, the major whey proteins were separated with perfect distinction of A and B β-lactoglobulin variants. Comparing to SDS-PAGE, a variation in the molecular weight was observed in all milk proteins. However, A and B β-lactoglobulin variants could not be isolated using SDS-PAGE. Although urea-PAGE did not show high resolution among whey proteins, γ-, κ-, β-, and α-caseins were clearly identified. This method also showed a lower limit detection of cow milk in mixture samples than the "lab-on-a-chip" electrophoresis. In both methods, the highest linearity obtained from plotting total percentage against cow milk concentration was observed by using cow αs1-casein (R2 = 0.986 and R² = 0.973). This result indicates that microfluidic electrophoresis is an effective tool to detect the presence of some proteins in goat and cow milk, and in mixtures. Microfluidic chip technology might will complement the current methods for analyzing milk proteins, highlighting its speed amount of reagents and whey protein separation, which showed a better result than urea or SDS-PAGE


Food systems ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 74-81
Author(s):  
A. V. Landikhovskaya ◽  
A. A. Tvorogova

The current state and new research trends of creating functional ice cream and frozen desserts are considered in the article. Attention is paid to the difference between the characteristics of ice cream regulated by the term in the countries of European Union and Eurasian Union. Taking into account that ice cream and frozen desserts are multicomponent products, the correction of their composition may have different effect on their quality indices. In particular, replacing sucrose by substitutes can lead to a change of traditional taste, consistency and structure. In this connection, aspects of the usage of sucrose substitutes by sweetness (glucose-fructose syrup, processed fruit products, stevia, sucrolose) and by dry matter (food fibers and polyols) are considered. In particular, the authors of researches note that the application of polyols changes the ice cream consistency to be firmer. The researchers pay attention to the impact of some components, introduced into ice cream and frozen desserts, on the cryoscopic temperature of mixture. The enrichment of ice cream and frozen desserts with pro- and prebiotics and application of milk with the increased nutritional value (sheep and goat milk) has been noted to be a trend in research. The attention is drawn to the practical use of enzymes. For people with lactose intolerance, the reason of which in ice cream is Nonfat milk solids (MSNF) it is proposed to hydrolyze it by different methods. In this review the experience of some scientists on the use of transglutaminase enzyme for changing properties of milk proteins, in particular, increasing their water- holding capacity is reflected. Researchers pay great attention to the increasing of nutritional value of ice cream and desserts by growth of mass fraction of protein and introduction of easily digestible proteins (concentrates of whey proteins, including the hydrolyzed proteins). Taking into consideration the growth of people who do not consume products of animal origin, some researches on replacement of milk protein to vegetable one, in particular, soy are noted.


2018 ◽  
Author(s):  
Yanhui Hu ◽  
Richelle Sopko ◽  
Verena Chung ◽  
Romain A. Studer ◽  
Sean D. Landry ◽  
...  

AbstractPost-translational modification (PTM) serves as a regulatory mechanism for protein function, influencing stability, protein interactions, activity and localization, and is critical in many signaling pathways. The best characterized PTM is phosphorylation, whereby a phosphate is added to an acceptor residue, commonly serine, threonine and tyrosine. As proteins are often phosphorylated at multiple sites, identifying those sites that are important for function is a challenging problem. Considering that many phosphorylation sites may be non-functional, prioritizing evolutionarily conserved phosphosites provides a general strategy to identify the putative functional sites with regards to regulation and function. To facilitate the identification of conserved phosphosites, we generated a large-scale phosphoproteomics dataset from Drosophila embryos collected from six closely-related species. We built iProteinDB (https://www.flyrnai.org/tools/iproteindb/), a resource integrating these data with other high-throughput PTM datasets, including vertebrates, and manually curated information for Drosophila. At iProteinDB, scientists can view the PTM landscape for any Drosophila protein and identify predicted functional phosphosites based on a comparative analysis of data from closely-related Drosophila species. Further, iProteinDB enables comparison of PTM data from Drosophila to that of orthologous proteins from other model organisms, including human, mouse, rat, Xenopus laevis, Danio rerio, and Caenorhabditis elegans.


Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 362
Author(s):  
Linda Le Roux ◽  
Olivia Ménard ◽  
Raphaël Chacon ◽  
Didier Dupont ◽  
Romain Jeantet ◽  
...  

Infant formulas (IFs) are used as substitutes for human milk and are mostly based on cow milk proteins. For sustainability reasons, animal protein alternatives in food are increasingly being considered, as plant proteins offer interesting nutritional and functional benefits for the development of innovative IFs. This study aimed to assess how a partial substitution (50%) of dairy proteins with faba bean and pea proteins influenced the digestibility of IFs under simulated dynamic in vitro digestion, which were set up to mimic infant digestion. Pea- and faba bean-based IFs (PIF and FIF, respectively) have led to a faster aggregation than the reference milk-based IF (RIF) in the gastric compartment; that did not affect the digesta microstructure at the end of digestion. The extent of proteolysis was estimated via the hydrolysis degree, which was the highest for FIF (73%) and the lowest for RIF (50%). Finally, it was apparent that in vitro protein digestibility and protein digestibility-corrected amino acid score (PDCAAS)-like scores were similar for RIF and FIF (90% digestibility; 75% PDCAAS), but lower for PIF (75%; 67%). Therefore, this study confirms that faba bean proteins could be a good candidate for partial substitution of whey proteins in IFs from a nutritional point of view, provided that these in vitro results are confirmed in vivo.


2013 ◽  
Vol 11 (04) ◽  
pp. 1350007 ◽  
Author(s):  
LIN HE ◽  
XI HAN ◽  
BIN MA

De novo sequencing derives the peptide sequence from a tandem mass spectrum without the assistance of protein databases. This analysis has been indispensable for the identification of novel or modified peptides in a biological sample. Currently, the speed of de novo sequencing algorithms is not heavily affected by the number of post-translational modification (PTM) types in consideration. However, the accuracy of the algorithms can be degraded due to the increased search space. Most peptides in a proteomics research contain only a small number of PTMs per peptide, yet the types of PTMs can come from a large number of choices. Therefore, it is desirable to include a large number of PTM types in a de novo sequencing algorithm, yet to limit the number of PTM occurrences in each peptide to increase the accuracy. In this paper, we present an efficient de novo sequencing algorithm, DeNovoPTM, for such a purpose. The implemented software is downloadable from http://www.cs.uwaterloo.ca/~l22he/denovo_ptm .


2014 ◽  
Vol 462 (1) ◽  
pp. 77-88 ◽  
Author(s):  
Kristen E. Funk ◽  
Stefani N. Thomas ◽  
Kelsey N. Schafer ◽  
Grace L. Cooper ◽  
Zhongping Liao ◽  
...  

Diverse post-translational modifications regulate tau protein function and misfolding. In the present study we identified lysine methylation as a tau post-translational modification in normal human brain, and found it depressed tau aggregation propensity when modelled in vitro.


2012 ◽  
Vol 52 ◽  
pp. 165-177 ◽  
Author(s):  
Daniel Schwartz

Our understanding of the importance of lysine post-translational modifications in mediating protein function has led to a significant improvement in the experimental tools aimed at characterizing their existence. Nevertheless, it remains likely that at present we have only experimentally detected a small fraction of all lysine modification sites across the commonly studied proteomes. As a result, online computational tools aimed at predicting lysine modification sites have the potential to provide valuable insight to researchers developing hypotheses regarding these modifications. This chapter discusses the metrics and procedures used to assess predictive tools and surveys 11 online computational tools aimed at the prediction of the four most widely studied lysine post-translational modifications (acetylation, methylation, SUMOylation and ubiquitination). Analyses using unbiased testing data sets suggest that nine of the 11 lysine post-translational modification tools perform no better than random, or have false-positive rates which make them unusable by the experimental biologist, despite self-reported sensitivity and specificity values to the contrary. The implications of these findings for those using and creating lysine post-translational modification software are discussed.


2021 ◽  
Vol 11 ◽  
Author(s):  
Carolina Alquezar ◽  
Shruti Arya ◽  
Aimee W. Kao

Post-translational modifications (PTMs) on tau have long been recognized as affecting protein function and contributing to neurodegeneration. The explosion of information on potential and observed PTMs on tau provides an opportunity to better understand these modifications in the context of tau homeostasis, which becomes perturbed with aging and disease. Prevailing views regard tau as a protein that undergoes abnormal phosphorylation prior to its accumulation into the toxic aggregates implicated in Alzheimer's disease (AD) and other tauopathies. However, the phosphorylation of tau may, in fact, represent part of the normal but interrupted function and catabolism of the protein. In addition to phosphorylation, tau undergoes another forms of post-translational modification including (but not limited to), acetylation, ubiquitination, glycation, glycosylation, SUMOylation, methylation, oxidation, and nitration. A holistic appreciation of how these PTMs regulate tau during health and are potentially hijacked in disease remains elusive. Recent studies have reinforced the idea that PTMs play a critical role in tau localization, protein-protein interactions, maintenance of levels, and modifying aggregate structure. These studies also provide tantalizing clues into the possibility that neurons actively choose how tau is post-translationally modified, in potentially competitive and combinatorial ways, to achieve broad, cellular programs commensurate with the distinctive environmental conditions found during development, aging, stress, and disease. Here, we review tau PTMs and describe what is currently known about their functional impacts. In addition, we classify these PTMs from the perspectives of protein localization, electrostatics, and stability, which all contribute to normal tau function and homeostasis. Finally, we assess the potential impact of tau PTMs on tau solubility and aggregation. Tau occupies an undoubtedly important position in the biology of neurodegenerative diseases. This review aims to provide an integrated perspective of how post-translational modifications actively, purposefully, and dynamically remodel tau function, clearance, and aggregation. In doing so, we hope to enable a more comprehensive understanding of tau PTMs that will positively impact future studies.


2011 ◽  
Vol 8 (5) ◽  
pp. 31-36
Author(s):  
Natal'ya Aleksandrovna Ivanova ◽  
G A Kuz'mina ◽  
L T Kochish ◽  
N N Begaeva ◽  
N M Afanas'eva ◽  
...  

Background. The research is focused on the particularities of formation and course of atopic dermatitis in infancy depending on the range of sensitization and class of revealed antibodies. Methods. The article presents the results of clinical and immunological observation of 116 children aged from 1 month to 3 years with the clinical-anamnestic signs of atopic dermatitis. The immunological observation consisted of the following stages: determination of concentration of the general IgE, quantitative testing of concentrations of the serum IgE and IgG4 antibodies to allergens of cow and goat milk, chicken eggs and wheat, house dust and through the immune-enzyme analysis. Results and discussion. According to the results of the immunological observation the patients were divided into 3 groups: I - IgE+IgG4 - positive, II - IgG4 - positive, III - absence of above-mentioned classes of antibodies. The patients of group I are characterized by the early sensitization to cow milk proteins, the manifestation of the disease up to 3 months appears on pure breast feeding. The detection of the specific IgE antibodies to allergens of chicken eggs is a sign of danger of the development of sensitization towards inhalation house dust allergens and of the formation of respiratory allergy. For the children of group II the later age of manifestation of skin process (in more than half of children after introduction of milk food) and easier course of disease are significant. Anamnesis of the disease and the clinical manifestations of one third of patients of group III in the absence of the evidence of IgE-sensitization coincides with that of the patients of group I (age of manifestation, severity of disease). In accordance with received results, we can suggest that in this group there are patients with the unidentified immunopathological mechanism of formation of the disease. Conclusion. The immunological observation of infants by the detection of the specific IgE and IgG4 antibodies to widespread food allergens allows to reveal the peculiarities of immune response which in their turn define the clinical-anamnestic signs of atopic dermatitis.


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