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Park MY, Kim S, Kwon NH, Moon G, Cha J, Kwon I. Enhanced anti-tumor activity of arginine decarboxylase through the incorporation of aromatic amino acids at the multimer-forming interface. Biotechnol J 2024; 19:e2300453. [PMID: 37899497 DOI: 10.1002/biot.202300453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/16/2023] [Accepted: 10/26/2023] [Indexed: 10/31/2023]
Abstract
The pressing challenge of cancer's high mortality and invasiveness demands improved therapeutic approaches. Targeting the nutrient dependencies within cancer cells has emerged as a promising approach. This study is dedicated to demonstrating the potential of arginine depletion for cancer treatment. Notably, the focus centers on arginine decarboxylase (RDC), a pH-dependent enzyme expecting enhanced activity within the slightly acidic microenvironments of tumors. To investigate the effect of a single-site mutation on the catalytic efficacy of RDC, diverse amino acids, including glycine, alanine, phenylalanine, tyrosine, tryptophan, p-azido-phenylalanine, and a phenylalanine analog with a hydrogen-substituted tetrazine, were introduced at the crucial threonine site (position 39) in the multimer-forming interface. Remarkably, the introduction of either a natural or a non-natural aromatic amino acid at position 39 substantially boosted enzymatic activity, while amino acids with smaller side chains did not show the same effect. This enhanced enzymatic activity is likely attributed to the reinforced formation of multimer structures through favorable interactions between the introduced aromatic amino acid and the neighboring subunit. Noteworthy, at slightly acidic pH, the RDC variant featuring tryptophan at position 39 demonstrated augmented cytotoxicity against tumor cells compared to the wild-type RDC. This attribute aligns with the tumor microenvironment and positions these variants as potential candidates for targeted cancer therapy.
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Affiliation(s)
- Min Yeong Park
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Seoungkyun Kim
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Na Hyun Kwon
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Giseok Moon
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Jaehyun Cha
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Inchan Kwon
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
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An Z, Yang D, Li M, Huo Y, Jiang J, Zhou Y, Ma Y, Hou W, Zhang J, He M. Hydroxylation of some emerging disinfection byproducts (DBPs) in water environment: Halogenation induced strong pH-dependency. J Hazard Mater 2023; 452:131233. [PMID: 36948122 DOI: 10.1016/j.jhazmat.2023.131233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/24/2023] [Accepted: 03/15/2023] [Indexed: 06/18/2023]
Abstract
In this work, the hydroxylation mechanisms and kinetics of some emerging disinfection byproducts (DBPs) have been systematically investigated through theoretical calculation methods. Five chlorophenols and eleven halogenated pyridinols were chosen as the model compounds to study their pH-dependent reaction laws in UV/H2O2 system. For the reactions of HO• with 37 different dissociation forms, radical adduct formation (RAF) was the main reaction pathway, and the reactivity decreased with the increase of halogenation degree. The kapp values (at 298 K) increased with the increase of pH from 0 to 10, and decreased with the increase of pH from 10 to 14. Compared with phenol, the larger the chlorination degree in chlorophenols was, the stronger the pH sensitivity of the kapp values; compared with chlorophenols, the pH sensitivity in halogenated pyridinols was further enhanced. As the pH increased from 2 to 10.5, the degradation efficiency increased at first and then decreased. With the increase of halogenation degree, the degradation efficiency range increased, the pH sensitivity increased, the optimal degradation efficiency slightly increased, and the optimal degradation pH value decreased. The ecotoxicity and bioaccumulation of most hydroxylated products were lower than their parental compounds. These findings provided meaningful insights into the strong pH-dependent hydroxylation of emerging DBPs on molecular level.
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Affiliation(s)
- Zexiu An
- College of Plant Protection, Hebei Agricultural University, Baoding 071000, China; Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Dongchen Yang
- College of Plant Protection, Hebei Agricultural University, Baoding 071000, China
| | - Mingxue Li
- Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Yanru Huo
- Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Jinchan Jiang
- Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Yuxin Zhou
- Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Yuhui Ma
- Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Wenlong Hou
- Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Jinlin Zhang
- College of Plant Protection, Hebei Agricultural University, Baoding 071000, China.
| | - Maoxia He
- Environment Research Institute, Shandong University, Qingdao 266237, China.
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Tang Q, Roos YH, Miao S. Plant Protein versus Dairy Proteins: A pH-Dependency Investigation on Their Structure and Functional Properties. Foods 2023; 12. [PMID: 36673460 DOI: 10.3390/foods12020368] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Plant proteins are constantly gaining attention as potential substitutes for dairy proteins, due to their suitable functionality and nutritional value. This study was designed to compare the structural and functional responses of different plant protein isolates (soy, pea, lentil, and chickpea) with two commonly used dairy protein (whey protein isolates and sodium caseinate) under different pH treatments (pH 3.0, 5.0, 7.0, and 9.0). The results showed that pH had a different alteration on the structural, surface properties and functional properties of plant and dairy proteins. Plant protein generally possessed a darker color, lower solubility, emulsifying properties, and foaming capacity, whereas their foaming stability and water holding capacity were higher than those of dairy proteins. Soy protein isolates were characterized by its comparable proportion of β-turn and random coils, zeta-potential, emulsifying (30.37 m2/g), and water-holding capacity (9.03 g/g) at alkaline conditions and chickpea protein isolates showed good oil-holding capacity (3.33 g/g at pH 9) among plant proteins. Further analysis confirmed that pH had a greater influence on the structural and functional properties of proteins as compared to protein sources, particularly at acidic conditions. Overall, this study might help processors select the appropriate plant protein as dairy alternatives for their target application in plant-based food products.
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Hebling E Tavares JP, da Silva Medeiros ML, Barbin DF. Near-infrared techniques for fraud detection in dairy products: A review. J Food Sci 2022; 87:1943-1960. [PMID: 35362099 DOI: 10.1111/1750-3841.16143] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 03/09/2022] [Accepted: 03/16/2022] [Indexed: 01/14/2023]
Abstract
The dairy products sector is an important part of the food industry, and their consumption is expected to grow in the next 10 years. Therefore, the authentication of these products in a faster and precise way is required for the sake of public health. This review proposes the use of near-infrared techniques for the detection of food fraud in dairy products as they are faster, nondestructive, environmentally friendly, do not require sample preparation, and allow multiconstituent analysis. First, we have described frequent forms of food fraud in dairy products and the application of traditional techniques for their detection, highlighting gaps and counterproductive characteristics for the actual global food chain, as longer sample preparation time and use of reagents. Then, the application of near-infrared spectroscopy and hyperspectral imaging for the detection of food fraud mainly in cheese, butter, and yogurt are described. As these techniques depend on model development, the coverage of different dairy products by the literature will promote the identification of food fraud in a faster and reliable way.
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Affiliation(s)
| | | | - Douglas Fernandes Barbin
- Department of Food Engineering, School of Food Engineering, University of Campinas, Campinas, Brazil
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Lee HW, Lu Y, Zhang Y, Fu C, Huang D. Physicochemical and functional properties of red lentil protein isolates from three origins at different pH. Food Chem 2021; 358:129749. [PMID: 33933978 DOI: 10.1016/j.foodchem.2021.129749] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 03/20/2021] [Accepted: 04/03/2021] [Indexed: 12/23/2022]
Abstract
Red lentils (Lens culinaris) present an attractive raw material for meat mimics due to its red-coloured proteins, abundance, high protein and low cost. However, data on its functional properties at various pH remain scarce. In this study, the physicochemical and functional properties of red lentil proteins (RLP) from three origins (USA, Nepal and Turkey), isolated by isoelectric precipitation, were evaluated. Amino acid profiles, water holding (ranging from 3.1 to 3.5 g/g) and oil absorption (ranging from 5.8 to 7.3 g/g) capacities of RLP samples were significantly different (p < 0.05). RLP consisted of legumin and vicilin, and comprised predominantly glutamine/glutamic acid (ranging from 8.72 to 10.55 g/100 g). Surface charge, protein solubility, foaming and emulsifying properties were the lowest and poorest at pH 5.2 (isoelectric point). Overall, good functional properties of RLP under high acidity and alkalinity conditions make it a promising protein for mimicking a wide range of meats.
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Affiliation(s)
- Hui Wen Lee
- Department of Food Science and Technology, National University of Singapore, Science Drive 2, Singapore 117542, Singapore.
| | - Yuyun Lu
- Department of Food Science and Technology, National University of Singapore, Science Drive 2, Singapore 117542, Singapore.
| | - Yuyu Zhang
- Beijing Key Laboratory of Flavour Chemistry, Beijing Technology and Business University (BTBU), Beijing 100048, China.
| | - Caili Fu
- National University of Singapore (Suzhou) Research Institute, 377 Linquan Street, Suzhou 215123, China.
| | - Dejian Huang
- Department of Food Science and Technology, National University of Singapore, Science Drive 2, Singapore 117542, Singapore; National University of Singapore (Suzhou) Research Institute, 377 Linquan Street, Suzhou 215123, China.
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Gomes P, Valente T, Geraldo D, Ribeiro C. Photosynthetic pigments in acid mine drainage: Seasonal patterns and associations with stressful abiotic characteristics. Chemosphere 2020; 239:124774. [PMID: 31521937 DOI: 10.1016/j.chemosphere.2019.124774] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/29/2019] [Accepted: 09/04/2019] [Indexed: 06/10/2023]
Abstract
Acid mine drainage represents an extreme type of water pollution. The environments develop especial hydrochemical and ecological characteristics, such as high concentrations of acidity and low biodiversity, with dominance of acidophilic organisms. Ecological criteria are assuming increasing relevance for assessing water quality, including in acid mine drainage-affected systems. Photosynthetic pigments, like chlorophyll, could be considered in this context as they are generally used to estimate phytoplankton biomass. The present work was focused on acid mine drainage and their relationships with chlorophyll a. It was developed in the historic mine of São Domingos (Iberian Pyrite Belt, SW Europe). The methodological approach comprised two sampling campaigns (October and February) to represent seasonal behaviour. The diversity of hydrological conditions was also considered through sampling sites established in the pit lake, acidic lagoons and affected stream. Hydrochemistry and chlorophyll a were analysed. The obtained results revealed very low pH values, with a minimum of 2.1. In general, hydrochemistry indicates higher concentrations of pollutants in summer. One of the sampling point, located in an acidic lagoon, stood out by highest concentrations, presenting maximum of sulfate (6564 mg/L), As (6.26 mg/L), and metals like Al (675 mg/L), Cd (1,30 mg/L), Zn (199 mg/L). These highest concentrations coincided with the maximum concentration of chlorophyll a (113 μg/L). The results suggested that the more contaminated the environment, more chlorophyll a was produced. Factor analyses emphasised the relationships between acid drainage properties and the photosynthetic activity, indicating a strong pH dependency of chlorophyll a production.
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Affiliation(s)
- Patrícia Gomes
- ICT, Institute of Earth Sciences, Pole of University of Minho, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Teresa Valente
- ICT, Institute of Earth Sciences, Pole of University of Minho, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
| | - Dulce Geraldo
- Chemistry Center, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Catarina Ribeiro
- Chemistry Center, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
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Ganjizade A, Sadeghi A, Ashrafizadeh SN. Effect of ion partitioning on electrostatics of soft particles with volumetrically charged inner core coated with pH-regulated polyelectrolyte layer. Colloids Surf B Biointerfaces 2018; 170:129-135. [PMID: 29894833 DOI: 10.1016/j.colsurfb.2018.05.053] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 05/09/2018] [Accepted: 05/23/2018] [Indexed: 01/18/2023]
Abstract
The effect of ion partitioning on the electrostatics of a soft particle with a volumetrically charged core and a pH-dependent polyelectrolyte layer (PEL) is numerically investigated. It is observed that, whenever the ion partitioning is noticeable, the soft layer can be fully charged in a broader range of pH. Besides, a higher number density of the PEL functional groups and a lower charge density of the core result in a sharper dependence of the electric potential on the electrolyte pH. Briefly, we conclude that, since the PEL charge is dependent upon the concentration of the hydroxide/hydrogen ions, for the pH-regulated soft particles, the ion partitioning effect, as a phenomenon influencing the ionic distribution, can be a determinant factor. So taking the effect of the ion partitioning into consideration is strongly recommended for a more realistic description of the electrostatics of the pH-regulated soft particles.
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Affiliation(s)
- Ardalan Ganjizade
- Research Lab for Advanced Separation Processes, Department of Chemical Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114, Iran.
| | - Arman Sadeghi
- Department of Mechanical Engineering, University of Kurdistan, Sanandaj 66177-15175, Iran.
| | - Seyed Nezameddin Ashrafizadeh
- Research Lab for Advanced Separation Processes, Department of Chemical Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114, Iran.
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Abstract
pH-dependent antibodies are engineered to release their target at a slightly acidic pH, a property making them suitable for clinical as well as biotechnological applications. Such antibodies were previously obtained by histidine scanning of pre-existing antibodies, a labor-intensive strategy resulting in antibodies that displayed residual binding to their target at pH 6.0. We report here the de novo isolation of pH-dependent antibodies selected by phage display from libraries enriched in histidines. Strongly pH-dependent clones with various affinity profiles against CXCL10 were isolated by this method. Our best candidate has nanomolar affinity for CXCL10 at pH 7.2, but no residual binding was detected at pH 6.0. We therefore propose that this new process is an efficient strategy to generate pH-dependent antibodies.
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Key Words
- BLI, bio-layer interferometry
- CDR, complementary determining region
- CDRH, CDR of the heavy chain
- CDRL, CDR of the light chain
- ELISA, enzyme-linked immunosorbent assay
- GPCR, G protein-coupled receptor
- KB, kinetic buffer
- PBS, phosphate buffered saline
- SPR, surface plasmon resonance
- antibody recycling
- chemokine
- histidine
- mAb, monoclonal antibody
- monoclonal antibody
- pH-dependency
- phage display
- phage libraries
- scFv, single-chain variable fragment
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