scholarly journals Peptidomics of potato protein hydrolysates: implications of post-translational modifications in food peptide structure and behaviour

2018 ◽  
Vol 5 (7) ◽  
pp. 172425 ◽  
Author(s):  
Shixiang Yao ◽  
Chibuike C. Udenigwe
Keyword(s):  
Protein Function ◽  
Biological Activities ◽  
Chemical Properties ◽  
Peptide Structure ◽  
Aqueous Environment ◽  
Methionine Oxidation ◽  
Food Protein ◽  
Potato Protein ◽  
Post Translational Modifications ◽  
Proteins And Peptides

Post-translational modifications (PTMs) often occur in proteins and play a regulatory role in protein function. There is an increasing interest in the bioactivity of food protein-derived peptides, but the occurrence of PTMs and their influence on food peptide structure and behaviour remain largely unknown. In this study, the shotgun-based peptidomics strategy was used to identify the occurrence of PTMs in peptides generated from potato protein hydrolysis using digestive proteases. Diverse PTMs were found in the potato peptides, including acetylation of lysine, N-terminal of proteins and peptides, C-terminal amidation, de-amidation of asparagine/glutamine, methylation and trimethylation, methionine oxidation and N-terminal pyro-glutamyl residue formation. The modifications may have been formed naturally or as a result of chemical reactions during isolation and enzymatic processing of the potato proteins. Most of the PTMs were calculated to decrease the isoelectric point and increase molecular hydrophobicity of the peptides, which will influence their bioactivity while also potentially altering their solubility in an aqueous environment. This is the first study to unravel that food-derived peptides can be widely modified by PTMs associated with notable changes in peptide chemical properties. The findings have broader implications on the bioavailability, biomolecular interactions and biological activities of food peptides.

Peptidomics analysis of potato protein hydrolysates: post-translational modifications and peptide hydrophobicity

2017 ◽  
Author(s):  
Shixiang Yao ◽  
Chibuike Udenigwe
Keyword(s):  
Protein Function ◽  
Structural Changes ◽  
Protein Hydrolysates ◽  
Proteolytic Processing ◽  
Methionine Oxidation ◽  
Potato Protein ◽  
Post Translational Modifications ◽  
Peptide Hydrophobicity ◽  
Proteins And Peptides

Post-translational modifications (PTMs) often <a></a><a>occur in proteins</a> and play a regulatory role in protein function. However, the role of PTMs in food-derived peptides remains largely unknown. The shotgun peptidomics strategy was employed to identify PTMs in peptides from potato protein hydrolysates. Various hydrophobicity-inducing PTMs were found to be located in different potato peptides, <i>e.g</i>. acetylation of lysine, N-terminal of proteins and peptides, C-terminal amidation, asparagine/glutamine deamidaiton, methylation and trimethylation, methionine oxidation, and N-terminal pyro-glutamate formation. Some of the PTMs are likely formed by chemical reactions that occur during isolation and proteolytic processing of potato proteins. The PTMs enhance peptide hydrophobicity, which can improve bioactivity, decrease solubility and increase the bitterness of peptides. This is the first report that food-derived peptides are widely modified by various PTMs associated with hydrophobicity-inducing structural changes. This finding will enhance understanding of the behaviour of bioactive peptides in biological matrices.

Peptidomics analysis of potato protein hydrolysates: post-translational modifications and peptide hydrophobicity

2017 ◽  
Author(s):  
Shixiang Yao ◽  
Chibuike Udenigwe
Keyword(s):  
Protein Function ◽  
Structural Changes ◽  
Protein Hydrolysates ◽  
Proteolytic Processing ◽  
Methionine Oxidation ◽  
Potato Protein ◽  
Post Translational Modifications ◽  
Peptide Hydrophobicity ◽  
Proteins And Peptides

Post-translational modifications (PTMs) often <a></a><a>occur in proteins</a> and play a regulatory role in protein function. However, the role of PTMs in food-derived peptides remains largely unknown. The shotgun peptidomics strategy was employed to identify PTMs in peptides from potato protein hydrolysates. Various hydrophobicity-inducing PTMs were found to be located in different potato peptides, <i>e.g</i>. acetylation of lysine, N-terminal of proteins and peptides, C-terminal amidation, asparagine/glutamine deamidaiton, methylation and trimethylation, methionine oxidation, and N-terminal pyro-glutamate formation. Some of the PTMs are likely formed by chemical reactions that occur during isolation and proteolytic processing of potato proteins. The PTMs enhance peptide hydrophobicity, which can improve bioactivity, decrease solubility and increase the bitterness of peptides. This is the first report that food-derived peptides are widely modified by various PTMs associated with hydrophobicity-inducing structural changes. This finding will enhance understanding of the behaviour of bioactive peptides in biological matrices.

The challenge of detecting modifications on proteins

2020 ◽  
Vol 64 (1) ◽  
pp. 135-153 ◽  
Author(s):  
Lauren Elizabeth Smith ◽  
Adelina Rogowska-Wrzesinska
Keyword(s):  
Mass Spectrometry ◽  
Protein Function ◽  
Chemical Properties ◽  
Lysine Acetylation ◽  
Mass Determination ◽  
Post Translational Modifications ◽  
Site Specific ◽  
The Common

Abstract Post-translational modifications (PTMs) are integral to the regulation of protein function, characterising their role in this process is vital to understanding how cells work in both healthy and diseased states. Mass spectrometry (MS) facilitates the mass determination and sequencing of peptides, and thereby also the detection of site-specific PTMs. However, numerous challenges in this field continue to persist. The diverse chemical properties, low abundance, labile nature and instability of many PTMs, in combination with the more practical issues of compatibility with MS and bioinformatics challenges, contribute to the arduous nature of their analysis. In this review, we present an overview of the established MS-based approaches for analysing PTMs and the common complications associated with their investigation, including examples of specific challenges focusing on phosphorylation, lysine acetylation and redox modifications.

Reading the phosphorylation code: binding of the 14-3-3 protein to multivalent client phosphoproteins

2020 ◽  
Vol 477 (7) ◽  
pp. 1219-1225 ◽  
Author(s):  
Nikolai N. Sluchanko
Keyword(s):  
Protein Function ◽  
Intrinsically Disordered Protein ◽  
Structural Basis ◽  
Major Protein ◽  
Post Translational Modifications ◽  
Protein Protein Interaction ◽  
Intrinsically Disordered ◽  
Biochemical Journal ◽  
Multiple Binding ◽  
And Control

Many major protein–protein interaction networks are maintained by ‘hub’ proteins with multiple binding partners, where interactions are often facilitated by intrinsically disordered protein regions that undergo post-translational modifications, such as phosphorylation. Phosphorylation can directly affect protein function and control recognition by proteins that ‘read’ the phosphorylation code, re-wiring the interactome. The eukaryotic 14-3-3 proteins recognizing multiple phosphoproteins nicely exemplify these concepts. Although recent studies established the biochemical and structural basis for the interaction of the 14-3-3 dimers with several phosphorylated clients, understanding their assembly with partners phosphorylated at multiple sites represents a challenge. Suboptimal sequence context around the phosphorylated residue may reduce binding affinity, resulting in quantitative differences for distinct phosphorylation sites, making hierarchy and priority in their binding rather uncertain. Recently, Stevers et al. [Biochemical Journal (2017) 474: 1273–1287] undertook a remarkable attempt to untangle the mechanism of 14-3-3 dimer binding to leucine-rich repeat kinase 2 (LRRK2) that contains multiple candidate 14-3-3-binding sites and is mutated in Parkinson's disease. By using the protein-peptide binding approach, the authors systematically analyzed affinities for a set of LRRK2 phosphopeptides, alone or in combination, to a 14-3-3 protein and determined crystal structures for 14-3-3 complexes with selected phosphopeptides. This study addresses a long-standing question in the 14-3-3 biology, unearthing a range of important details that are relevant for understanding binding mechanisms of other polyvalent proteins.

scholarly journals Lignans of Sesame (Sesamum indicum L.): A Comprehensive Review

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 883
Author(s):  
Mebeaselassie Andargie ◽  
Maria Vinas ◽  
Anna Rathgeb ◽  
Evelyn Möller ◽  
Petr Karlovsky
Keyword(s):  
Biological Activities ◽  
Chemical Properties ◽  
Transformation Products ◽  
Extensive Literature ◽  
Controversial Issues ◽  
Sesame Seeds ◽  
Historical Texts ◽  
Health Promoting ◽  
Processed Products

Major lignans of sesame sesamin and sesamolin are benzodioxol--substituted furofurans. Sesamol, sesaminol, its epimers, and episesamin are transformation products found in processed products. Synthetic routes to all lignans are known but only sesamol is synthesized industrially. Biosynthesis of furofuran lignans begins with the dimerization of coniferyl alcohol, followed by the formation of dioxoles, oxidation, and glycosylation. Most genes of the lignan pathway in sesame have been identified but the inheritance of lignan content is poorly understood. Health-promoting properties make lignans attractive components of functional food. Lignans enhance the efficiency of insecticides and possess antifeedant activity, but their biological function in plants remains hypothetical. In this work, extensive literature including historical texts is reviewed, controversial issues are critically examined, and errors perpetuated in literature are corrected. The following aspects are covered: chemical properties and transformations of lignans; analysis, purification, and total synthesis; occurrence in Seseamum indicum and related plants; biosynthesis and genetics; biological activities; health-promoting properties; and biological functions. Finally, the improvement of lignan content in sesame seeds by breeding and biotechnology and the potential of hairy roots for manufacturing lignans in vitro are outlined.

scholarly journals Proteomic Advances in Milk and Dairy Products

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3832
Author(s):  
Rubén Agregán ◽  
Noemí Echegaray ◽  
María López-Pedrouso ◽  
Radwan Kharabsheh ◽  
Daniel Franco ◽  
...  
Keyword(s):  
Dairy Products ◽  
Two Dimensional Gel Electrophoresis ◽  
Vast Number ◽  
Post Translational Modifications ◽  
Fundamental Parameters ◽  
Complex Fluid ◽  
Proteins And Peptides ◽  
Milk And Dairy Products

Proteomics is a new area of study that in recent decades has provided great advances in the field of medicine. However, its enormous potential for the study of proteomes makes it also applicable to other areas of science. Milk is a highly heterogeneous and complex fluid, where there are numerous genetic variants and isoforms with post-translational modifications (PTMs). Due to the vast number of proteins and peptides existing in its matrix, proteomics is presented as a powerful tool for the characterization of milk samples and their products. The technology developed to date for the separation and characterization of the milk proteome, such as two-dimensional gel electrophoresis (2DE) technology and especially mass spectrometry (MS) have allowed an exhaustive characterization of the proteins and peptides present in milk and dairy products with enormous applications in the industry for the control of fundamental parameters, such as microbiological safety, the guarantee of authenticity, or the control of the transformations carried out, aimed to increase the quality of the final product.

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

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
P. K. Rout ◽  
M. Verma
Keyword(s):  
Protein Function ◽  
Whey Proteins ◽  
Milk Proteins ◽  
Goat Milk ◽  
Peptide Sequence ◽  
Cow Milk ◽  
Post Translational Modification ◽  
Post Translational Modifications ◽  
Functional Roles ◽  
Dpp Iv

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.

scholarly journals Influence of pH, Temperature and Protease Inhibitors on Kinetics and Mechanism of Thermally Induced Aggregation of Potato Proteins

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 796
Author(s):  
David J. Andlinger ◽  
Pauline Röscheisen ◽  
Claudia Hengst ◽  
Ulrich Kulozik
Keyword(s):  
Protein Interactions ◽  
Disulfide Bonds ◽  
Food Systems ◽  
Disulfide Bridge ◽  
Food Protein ◽  
Potato Protein ◽  
Covalent Bonds ◽  
Bridge Formation ◽  
Induced Aggregation ◽  
Influence Of Ph

Understanding aggregation in food protein systems is essential to control processes ranging from the stabilization of colloidal dispersions to the formation of macroscopic gels. Patatin rich potato protein isolates (PPI) have promising techno-functionality as alternatives to established proteins from egg white or milk. In this work, the influence of pH and temperature on the kinetics of PPI denaturation and aggregation was investigated as an option for targeted functionalization. At a slightly acidic pH, rates of denaturation and aggregation of the globular patatin in PPI were fast. These aggregates were shown to possess a low amount of disulfide bonds and a high amount of exposed hydrophobic amino acids (S0). Gradually increasing the pH slowed down the rate of denaturation and aggregation and alkaline pH levels led to an increased formation of disulfide bonds within these aggregates, whereas S0 was reduced. Aggregation below denaturation temperature (Td) favored aggregation driven by disulfide bridge formation. Aggregation above Td led to fast unfolding, and initial aggregation was less determined by disulfide bridge formation. Inter-molecular disulfide formation occurred during extended heating times. Blocking different protein interactions revealed that the formation of disulfide bond linked aggregation is preceded by the formation of non-covalent bonds. Overall, the results help to control the kinetics, morphology, and interactions of potato protein aggregation for potential applications in food systems.

scholarly journals Green Silver and Gold Nanoparticles: Biological Synthesis Approaches and Potentials for Biomedical Applications

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 844 ◽  
Author(s):  
Andrea Rónavári ◽  
Nóra Igaz ◽  
Dóra I. Adamecz ◽  
Bettina Szerencsés ◽  
Csaba Molnar ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Biomedical Applications ◽  
Biological Activities ◽  
Large Body ◽  
Chemical Properties ◽  
Biological Synthesis ◽  
Silver And Gold Nanoparticles ◽  
Comprehensive Collection ◽  
Synthetic Approaches ◽  
Physical And Chemical

The nanomaterial industry generates gigantic quantities of metal-based nanomaterials for various technological and biomedical applications; however, concomitantly, it places a massive burden on the environment by utilizing toxic chemicals for the production process and leaving hazardous waste materials behind. Moreover, the employed, often unpleasant chemicals can affect the biocompatibility of the generated particles and severely restrict their application possibilities. On these grounds, green synthetic approaches have emerged, offering eco-friendly, sustainable, nature-derived alternative production methods, thus attenuating the ecological footprint of the nanomaterial industry. In the last decade, a plethora of biological materials has been tested to probe their suitability for nanomaterial synthesis. Although most of these approaches were successful, a large body of evidence indicates that the green material or entity used for the production would substantially define the physical and chemical properties and as a consequence, the biological activities of the obtained nanomaterials. The present review provides a comprehensive collection of the most recent green methodologies, surveys the major nanoparticle characterization techniques and screens the effects triggered by the obtained nanomaterials in various living systems to give an impression on the biomedical potential of green synthesized silver and gold nanoparticles.

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