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Hansda B, Mishra S, Ghosh A, Das B, Biswas T, Mondal TK, Srivastava B, Mondal S, Roy D, Mandal B. Chemically Bonded Pepsin via Its Inert Center to Diazo Functionalized Silica Gel through Multipoint Attachment Mode: A Way of Restoring Biocatalytic Sustainability over "Wider pH" Range. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:2146-2164. [PMID: 38240266 DOI: 10.1021/acs.langmuir.3c03113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2024]
Abstract
Proteolytic enzymes play a pivotal role in the industry. Still, because of denaturation, the extensive applicability at their level of best catalytic efficiency over a more comprehensive pH range, particularly in alkaline conditions over pH 8, has not been fully developed. On the other hand, enzyme immobilization following a suitable protocol is a long pending issue that determines the conformational stability, specificity, selectivity, enantioselectivity, and activity of the native enzymes at long-range pH. As a bridge between these two findings, in an attempt at a freezing temperature 273-278 K at an alkaline pH, the diazo-functionalized silica gel (SG) surface has been used to rapidly diazo couple pepsin through its inert center, the O-carbon of the phenolic -OH of surface-occupied Tyr residues in a multipoint mode: when all the various protein groups, viz., amino, thiol, phenol, imidazole, carboxy, etc., in the molecular sequence including those belonging to the active sites, remain intact, the inherent inbuilt interactions among themselves remain. Thereby, the macromolecule's global conformation and helicity preserve the status quo. The dimension of the SG-enzyme conjugate confirms as {Si(OSi)4 (H2O)1.03}n {-O-Si(CH3)2-O-C6H4-N═N+}4·{pepsin}·yH2O; where the values of n and y have been determined respectively as 347 and 188. The material performs the catalytic activity much better at 7-8.5 than at pH 2-3.5 and continues for up to six months without any appreciable change.
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Affiliation(s)
- Biswajit Hansda
- Analytical and Bio-analytical Laboratory, Department of Chemistry, Visva-Bharati, Santiniketan, West Bengal 731235, India
| | - Shailja Mishra
- Analytical and Bio-analytical Laboratory, Department of Chemistry, Visva-Bharati, Santiniketan, West Bengal 731235, India
| | - Ankit Ghosh
- Analytical and Bio-analytical Laboratory, Department of Chemistry, Visva-Bharati, Santiniketan, West Bengal 731235, India
| | - Basudev Das
- Analytical and Bio-analytical Laboratory, Department of Chemistry, Visva-Bharati, Santiniketan, West Bengal 731235, India
| | - Tirtha Biswas
- Analytical and Bio-analytical Laboratory, Department of Chemistry, Visva-Bharati, Santiniketan, West Bengal 731235, India
| | - Tanay K Mondal
- Analytical and Bio-analytical Laboratory, Department of Chemistry, Visva-Bharati, Santiniketan, West Bengal 731235, India
| | - Bhavya Srivastava
- The West Bengal National University of Juridical Sciences, Dr. Ambedkar Bhavan, Kolkata 700098, India
| | - Sneha Mondal
- Analytical and Bio-analytical Laboratory, Department of Chemistry, Visva-Bharati, Santiniketan, West Bengal 731235, India
| | - Dipika Roy
- Department of Chemistry, Jadavpur University, Main Campus 188, Raja S.C. Mallick Rd, Kolkata, West Bengal700032, India
| | - Bhabatosh Mandal
- Analytical and Bio-analytical Laboratory, Department of Chemistry, Visva-Bharati, Santiniketan, West Bengal 731235, India
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Itkonen J, Ghemtio L, Pellegrino D, Jokela (née Heinonen) PJ, Xhaard H, Casteleijn MG. Analysis of Biologics Molecular Descriptors towards Predictive Modelling for Protein Drug Development Using Time-Gated Raman Spectroscopy. Pharmaceutics 2022; 14:1639. [PMID: 36015265 PMCID: PMC9413954 DOI: 10.3390/pharmaceutics14081639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 06/29/2022] [Accepted: 08/03/2022] [Indexed: 11/16/2022] Open
Abstract
Pharmaceutical proteins, compared to small molecular weight drugs, are relatively fragile molecules, thus necessitating monitoring protein unfolding and aggregation during production and post-marketing. Currently, many analytical techniques take offline measurements, which cannot directly assess protein folding during production and unfolding during processing and storage. In addition, several orthogonal techniques are needed during production and market surveillance. In this study, we introduce the use of time-gated Raman spectroscopy to identify molecular descriptors of protein unfolding. Raman spectroscopy can measure the unfolding of proteins in-line and in real-time without labels. Using K-means clustering and PCA analysis, we could correlate local unfolding events with traditional analytical methods. This is the first step toward predictive modeling of unfolding events of proteins during production and storage.
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Affiliation(s)
- Jaakko Itkonen
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, 00100 Helsinki, Finland
| | - Leo Ghemtio
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, 00100 Helsinki, Finland
| | - Daniela Pellegrino
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, 00100 Helsinki, Finland
| | - Pia J. Jokela (née Heinonen)
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, 00100 Helsinki, Finland
- Orion Pharma, 02101 Espoo, Finland
| | - Henri Xhaard
- Drug Research Program, Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, 00100 Helsinki, Finland
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Grahame DAS, Dupuis JH, Bryksa BC, Tanaka T, Yada RY. Improving the alkaline stability of pepsin through rational protein design using renin, an alkaline-stable aspartic protease, as a structural and functional reference. Enzyme Microb Technol 2021; 150:109871. [PMID: 34489030 DOI: 10.1016/j.enzmictec.2021.109871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/28/2021] [Accepted: 07/12/2021] [Indexed: 10/20/2022]
Abstract
The present study sought to identify the structural determinants of aspartic protease structural stability and activity at elevated pH. Various hypotheses have been published regarding the features responsible for the unusual alkaline structural stability of renin, however, few structure-function studies have verified these claims. Using pepsin as a model system, and renin as a template for functional and structural alkaline stability, a rational re-design of pepsin was undertaken to identify residues contributing to the alkaline instability of pepsin-like aspartic proteases in regards to both structure and function. We constructed 13 mutants based on this strategy. Among them, mutants D159 L and D60A led to an increase in activity at elevated pH levels (p ≤ 0.05) and E4V and H53F were shown to retain native-like structure at elevated pH (p ≤ 0.05). Previously suggested carboxyl groups Asp11, Asp118, and Glu13 were individually shown not to be responsible for the structural instability or lack of activity at neutral pH in pepsin. The importance of the β-barrel to structural stability was highlighted as the majority of the stabilizing residues identified, and 39% of the weakly conserved residues in the N-terminal lobe, were located in β-sheet strands of the barrel. The results of the present study indicate that alkaline stabilization of pepsin will require reduction of electrostatic repulsions and an improved understanding of the role of the hydrogen bonding network of the characteristic β-barrel.
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Affiliation(s)
- Douglas A S Grahame
- Department of Food Science, Ontario Agricultural College, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - John H Dupuis
- Food, Nutrition, and Health Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Brian C Bryksa
- Department of Food Science, Ontario Agricultural College, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Takuji Tanaka
- Department of Food and Bioproduct Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, S7N 5A8, Canada
| | - Rickey Y Yada
- Food, Nutrition, and Health Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
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Somaratne G, Nau F, Ferrua MJ, Singh J, Ye A, Dupont D, Singh RP, Floury J. Characterization of egg white gel microstructure and its relationship with pepsin diffusivity. Food Hydrocoll 2020. [DOI: 10.1016/j.foodhyd.2019.105258] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Gohi BFCA, Zeng HY, Pan AD, Han J, Yuan J. pH Dependence of Chitosan Enzymolysis. Polymers (Basel) 2017; 9:E174. [PMID: 30970852 PMCID: PMC6432485 DOI: 10.3390/polym9050174] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 05/05/2017] [Accepted: 05/11/2017] [Indexed: 12/22/2022] Open
Abstract
As a means of making chitosan more useful in biotechnological applications, it was hydrolyzed using pepsin, chitosanase and α-amylase. The enzymolysis behavior of these enzymes was further systematically studied for its effectiveness in the production of low-molecular-weight chitosans (LMWCs) and other derivatives. The study showed that these enzymes depend on ion hydronium (H3O+), thus on pH with a pH dependence fitting R2 value of 0.99. In y = 1.484[H^+] + 0.114, the equation of pH dependence, when [H^+] increases by one, y (k_0/k_m) increases by 1.484. From the temperature dependence study, the activation energy (Ea) and pre-exponential factor (A) were almost identical for two of the enzymes, but a considerable difference was observed in comparison with the third enzyme. Chitosanase and pepsin had nearly identical Ea, but α-amylase was significantly lower. This serves as evidence that the hydrolysis reaction of α-amylase relies on low-barrier hydrogen bonds (LBHBs), which explains its low Ea in actual conditions. The confirmation of this phenomenon was further derived from a similarly considerable difference in the order magnitudes of A between α-amylase and the other two enzymes, which was more than five. Variation of the rate constants of the enzymatic hydrolysis of chitosan with temperature follows the Arrhenius equation.
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Affiliation(s)
- Bi Foua Claude Alain Gohi
- Biotechnology Institute, College of Chemical Engineering, Xiangtan University, Xiangtan 411105, Hunan, China.
| | - Hong-Yan Zeng
- Biotechnology Institute, College of Chemical Engineering, Xiangtan University, Xiangtan 411105, Hunan, China.
| | - A Dan Pan
- Biotechnology Institute, College of Chemical Engineering, Xiangtan University, Xiangtan 411105, Hunan, China.
| | - Jing Han
- Biotechnology Institute, College of Chemical Engineering, Xiangtan University, Xiangtan 411105, Hunan, China.
| | - Jian Yuan
- Biotechnology Institute, College of Chemical Engineering, Xiangtan University, Xiangtan 411105, Hunan, China.
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Ault AP, Stark DI, Axson JL, Keeney JN, Maynard AD, Bergin IL, Philbert MA. Protein Corona-Induced Modification of Silver Nanoparticle Aggregation in Simulated Gastric Fluid. ENVIRONMENTAL SCIENCE. NANO 2016; 3:1510-1520. [PMID: 28357114 PMCID: PMC5366255 DOI: 10.1039/c6en00278a] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Due to their widespread incorporation into a range of biomedical and consumer products, the ingestion of silver nanoparticles (AgNPs) is of considerable concern to human health. However, the extent to which AgNPs will be modified within the gastric compartment of the gastrointestinal tract is still poorly understood. Studies have yet to fully evaluate the extent of physicochemical changes to AgNPs in the presence of biological macromolecules, such as pepsin, the most abundant protein in the stomach, or the influence of AgNPs on protein structure and activity. Herein, AgNPs of two different sizes and surface coatings (20 and 110 nm, citrate or polyvinylpyrrolidone) were added to simulated gastric fluid (SGF) with or without porcine pepsin at three pHs (2.0, 3.5, and 5.0), representing a range of values between preprandial (fasted) and postprandial (fed) conditions. Rapid increases in diameter were observed for all AgNPs, with a greater increase in diameter in the presence of pepsin, indicating that pepsin facilitated AgNPs aggregation. AgNPs interaction with pepsin only minimally reduced the protein's proteolytic functioning capability, with the greatest inhibitory effect caused by smaller (20 nm) particles of both coatings. No changes in pepsin secondary structural elements were observed for the different AgNPs, even at high particle concentrations. This research highlights the size-dependent kinetics of nanoparticle aggregation or dissolution from interaction with biological elements such as proteins in the gastrointestinal tract. Further, these results demonstrate that, in addition to mass, knowing the chemical form and aggregation state of nanoparticles is critical when evaluating toxicological effects from nanoparticle exposure in the body.
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Affiliation(s)
- Andrew P Ault
- Department of Environmental Health Sciences, University of Michigan, Ann Arbor, MI; Department of Chemistry, University of Michigan, Ann Arbor, MI
| | - Diana I Stark
- Department of Environmental Health Sciences, University of Michigan, Ann Arbor, MI
| | - Jessica L Axson
- Department of Environmental Health Sciences, University of Michigan, Ann Arbor, MI
| | - Justin N Keeney
- Department of Chemistry, University of Michigan, Ann Arbor, MI
| | - Andrew D Maynard
- Department of Environmental Health Sciences, University of Michigan, Ann Arbor, MI
| | - Ingrid L Bergin
- Unit for Laboratory Animal Medicine, School of Medicine, University of Michigan, Ann Arbor, MI
| | - Martin A Philbert
- Department of Environmental Health Sciences, University of Michigan, Ann Arbor, MI
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Szałapata K, Osińska-Jaroszuk M, Bryjak J, Jaszek M, Jarosz-Wilkołazka A. NOVEL APPLICATION OF POROUS AND CELLULAR MATERIALS FOR COVALENT IMMOBILIZATION OF PEPSIN. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2016. [DOI: 10.1590/0104-6632.20160332s20140111] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
| | | | - J. Bryjak
- Wroclaw University of Technology, Poland
| | - M. Jaszek
- Maria Curie-Sklodowska University, Poland
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Foldase and inhibitor functionalities of the pepsinogen prosegment are encoded within discrete segments of the 44 residue domain. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1300-6. [PMID: 26003941 DOI: 10.1016/j.bbapap.2015.05.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Revised: 05/09/2015] [Accepted: 05/13/2015] [Indexed: 11/22/2022]
Abstract
Pepsin is initially produced as the zymogen pepsinogen, containing a 44 residue prosegment (PS) domain. When folded without the PS, pepsin forms a thermodynamically stable denatured state (refolded pepsin, Rp). To guide native folding, the PS binds to Rp, stabilizes the folding transition state, and binds tightly to native pepsin (Np), thereby driving the folding equilibrium to favor the native state. It is unknown whether these functionalities of the PS are encoded within the entire sequence or within discrete segments. PS residues 1p-29p correspond to a highly conserved region in pepsin-like aspartic proteases and we hypothesized that this segment is critical to PS-catalyzed folding. This notion was tested in the present study by characterizing the ability of various truncated PS peptides to bind Rp, catalyze folding from Rp to Np, and to inhibit Np. Four PS truncations were examined, corresponding to PS residues 1p-16p (PS1-16), 1p-29p (PS1-29), 17p-44p (PS17-44) and 30p-44p (PS30-44). The three PS functionalities could be ascribed primarily to discrete regions within the highly conserved motif: 1p-16p dictated Rp binding, 17p-29p dictated Np binding/inhibition, while the entire 1p-29p dictated transition state binding/catalyzing folding. Conversely, PS30-44 played no obvious role in PS-catalyzed folding; it is hypothesized that this more variable region may serve as a linker between PS1-29 and the mature domain. The high sequence conservation of PS1-29 and its role in catalyzing pepsin folding strongly suggest that there is a conserved PS-catalyzed folding mechanism shared by pepsin-like aspartic proteases with this motif.
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10
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Jityuti B, Buranaprapuk A, Liwporncharoenvong T. Artificial metallopeptidases: Protein cleavage by molybdenum(VI) peroxo α-amino acid complexes. INORG CHEM COMMUN 2015. [DOI: 10.1016/j.inoche.2015.03.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Meridor D, Gedanken A. Enhanced activity of immobilized pepsin nanoparticles coated on solid substrates compared to free pepsin. Enzyme Microb Technol 2014; 67:67-76. [DOI: 10.1016/j.enzmictec.2014.09.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 08/20/2014] [Accepted: 09/12/2014] [Indexed: 10/24/2022]
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12
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Peng G, Meng X, Wang B, Liu B, Chen H. The Surface Characteristics of Chitosan Modified PSt-GMA Microspheres Influenced the Interactions and Properties of Immobilized Pepsin. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 2014. [DOI: 10.1080/10601325.2014.976745] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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13
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Wang S, Horimoto Y, Dee DR, Yada RY. Understanding the mechanism of prosegment-catalyzed folding by solution NMR spectroscopy. J Biol Chem 2014; 289:697-707. [PMID: 24265313 DOI: 10.1074/jbc.m113.505891] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Multidomain protein folding is often more complex than a two-state process, which leads to the spontaneous folding of the native state. Pepsin, a zymogen-derived enzyme, without its prosegment (PS), is irreversibly denatured and folds to a thermodynamically stable, non-native conformation, termed refolded pepsin, which is separated from native pepsin by a large activation barrier. While it is known that PS binds refolded pepsin and catalyzes its conversion to the native form, little structural details are known regarding this conversion. In this study, solution NMR was used to elucidate the PS-catalyzed folding mechanism by examining the key equilibrium states, e.g. native and refolded pepsin, both in the free and PS-bound states, and pepsinogen, the zymogen form of pepsin. Refolded pepsin was found to be partially structured and lacked the correct domain-domain structure and active-site cleft formed in the native state. Analysis of chemical shift data revealed that upon PS binding refolded pepsin folds into a state more similar to that of pepsinogen than to native pepsin. Comparison of pepsin folding by wild-type and mutant PSs, including a double mutant PS, indicated that hydrophobic interactions between residues of prosegment and refolded pepsin lower the folding activation barrier. A mechanism is proposed for the binding of PS to refolded pepsin and how the formation of the native structure is mediated.
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Shobha MS, Gowda LR, Tharanathan RN. A novel catalysis by porcine pepsin in debranching guar galactomannan. Carbohydr Polym 2013; 102:615-21. [PMID: 24507326 DOI: 10.1016/j.carbpol.2013.11.043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 11/16/2013] [Accepted: 11/27/2013] [Indexed: 11/29/2022]
Abstract
BACKGROUND Pepsin (porcine stomach mucosa, E.C. 3.4.23.1), an acid protease catalyzes the hydrolysis (debranching) of guar galactomannan (GG), a co-polymer of mannose and galactose residues thereby showing its non-specific catalysis towards glycosidic substrates. RESULTS AND CONCLUSIONS Use of non-specific inhibitors, chemical modification agents and peptide mapping of native and GG--bound pepsin upon proteolytic digestion with Staphylococcus aureus V8 protease revealed the involvement of Asp(138) residue in the catalysis, which was confirmed by computational modelling studies. GENERAL SIGNIFICANCE Here we show a novel mode of catalysis (other than proteolysis) by porcine pepsin with a different active site residue.
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Affiliation(s)
- Mysore S Shobha
- Department of Biochemistry and Nutrition, Central Food Technological Research Institute, Council of Scientific and Industrial Research, Mysore 570 020, India
| | - Lalitha R Gowda
- Department of Protein Chemistry and Technology, Central Food Technological Research Institute, Council of Scientific and Industrial Research, Mysore 570 020, India
| | - Rudrapatam N Tharanathan
- Department of Biochemistry and Nutrition, Central Food Technological Research Institute, Council of Scientific and Industrial Research, Mysore 570 020, India.
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Shanmugam G, Selvi CC, Mandal AB. Ethanol and acetonitrile induces conformational changes in porcine pepsin at alkaline denatured state. Int J Biol Macromol 2012; 51:590-6. [DOI: 10.1016/j.ijbiomac.2012.06.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 06/18/2012] [Accepted: 06/19/2012] [Indexed: 11/25/2022]
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Yah WO, Yamamoto K, Jiravanichanun N, Otsuka H, Takahara A. Imogolite Reinforced Nanocomposites: Multifaceted Green Materials. MATERIALS 2010. [PMCID: PMC5445889 DOI: 10.3390/ma3031709] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This paper presents an overview on recent developments of imogolite reinforced nanocomposites, including fundamental structure, synthesis/purification of imogolite, physicochemical properties of nanocomposites and potential applications in industry. The naturally derived nanotubular material of imogolite represents a distinctive class of nanofiller for industrially significant polymer. The incompatibility between the surface properties of inorganic nanofiller and organic matrix has prompted the need to surface modify the imogolite. Early problems in increasing the binding properties of surface modifier to imogolite have been overcome by using a phosphonic acid group. Different approaches have been used to gain better control over the dispersal of nanofiller and to further improve the physicochemical properties of nanocomposites. Among these, polymer grafting, in situ synthesis of imogolite in polymer matrix, and spin-assembly are some of the promising methods that will be described herein. This imogolite reinforced nanocomposite of enhanced optical and mechanical properties, and with unique biological and electronic properties, is expected to become an important category of hybrid material that shows potential for industrial applications.
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Affiliation(s)
- Weng On Yah
- Graduate School of Engineering, Kyushu University, 744 Mootoka, Nishi-ku, Fukuoka 819-0395, Japan; E-Mail: (W.O.Y)
| | - Kazuya Yamamoto
- Kitakyushu College of Technology, 5-20-1 Shii, Kokuraminami, Kitakyusyu, Fukuoka 802-0985, Japan; E-Mail: (K.Y)
| | - Nattha Jiravanichanun
- Institute for Materials Chemistry and Engineering, Kyushu University, 744 Mootoka, Nishi-ku, Fukuoka 819-0395, Japan; E-Mails: (N.J); (H.O)
| | - Hideyuki Otsuka
- Graduate School of Engineering, Kyushu University, 744 Mootoka, Nishi-ku, Fukuoka 819-0395, Japan; E-Mail: (W.O.Y)
- Institute for Materials Chemistry and Engineering, Kyushu University, 744 Mootoka, Nishi-ku, Fukuoka 819-0395, Japan; E-Mails: (N.J); (H.O)
| | - Atsushi Takahara
- Graduate School of Engineering, Kyushu University, 744 Mootoka, Nishi-ku, Fukuoka 819-0395, Japan; E-Mail: (W.O.Y)
- Institute for Materials Chemistry and Engineering, Kyushu University, 744 Mootoka, Nishi-ku, Fukuoka 819-0395, Japan; E-Mails: (N.J); (H.O)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +81-92-802-2517; Fax: +81-92-802-2518
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Dee DR, Yada RY. The prosegment catalyzes pepsin folding to a kinetically trapped native state. Biochemistry 2010; 49:365-71. [PMID: 20000477 DOI: 10.1021/bi9014055] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Investigations of irreversible protein unfolding often assume that alterations to the unfolded state, rather than the nature of the native state itself, are the cause of the irreversibility. However, the present study describes a less common explanation for the irreversible denaturation of pepsin, a zymogen-derived aspartic peptidase. The presence of a large folding barrier combined with the thermodynamically metastable nature of the native state, the formation of which depends on a separate prosegment (PS) domain, is the source of the irreversibility. Pepsin is unable to refold to the native state upon return from denaturing conditions due to a large folding barrier (24.6 kcal/mol) and instead forms a thermodynamically stable, yet inactive, refolded state. The native state is kinetically stabilized by an unfolding activation energy of 24.5 kcal/mol, comparable to the folding barrier, indicating that native pepsin exists as a thermodynamically metastable state. However, in the presence of the PS, the native state becomes thermodynamically stable, and the PS catalyzes pepsin folding by stabilizing the folding transition state by 14.7 kcal/mol. Once folded, the PS is removed, and the native conformation exists as a kinetically trapped state. Thus, while PS-guided folding is thermodynamically driven, without the PS the pepsin energy landscape is dominated by kinetic barriers rather than by free energy differences between native and denatured states. As pepsin is the archetype of a broad class of aspartic peptidases of similar structure and function, and many require their PS for correct folding, these results suggest that the occurrence of native states optimized for kinetic rather than thermodynamic stability may be a common feature of protein design.
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Affiliation(s)
- Derek R Dee
- Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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18
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Acetonitrile-induced unfolding of porcine pepsin A. Int J Biol Macromol 2009; 45:213-20. [DOI: 10.1016/j.ijbiomac.2009.05.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 05/12/2009] [Accepted: 05/15/2009] [Indexed: 11/20/2022]
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19
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Pande M, Prasanna Kumari N, Dubey VK, Tripathi P, Jagannadham M. Stability and unfolding studies on alkaline denatured state (Ip) of pepsin. Process Biochem 2009. [DOI: 10.1016/j.procbio.2009.04.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Should digestion assays be used to estimate persistence of potential allergens in tests for safety of novel food proteins? Clin Mol Allergy 2009; 7:1. [PMID: 19146693 PMCID: PMC2632610 DOI: 10.1186/1476-7961-7-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Accepted: 01/15/2009] [Indexed: 12/20/2022] Open
Abstract
Food allergies affect an estimated 3 to 4% of adults and up to 8% of children in developed western countries. Results from in vitro simulated gastric digestion studies with purified proteins are routinely used to assess the allergenic potential of novel food proteins. The digestion of purified proteins in simulated gastric fluid typically progresses in an exponential fashion allowing persistence to be quantified using pseudo-first-order rate constants or half lives. However, the persistence of purified proteins in simulated gastric fluid is a poor predictor of the allergenic status of food proteins, potentially due to food matrix effects that can be significant in vivo. The evaluation of the persistence of novel proteins in whole, prepared food exposed to simulated gastric fluid may provide a more correlative result, but such assays should be thoroughly validated to demonstrate a predictive capacity before they are accepted to predict the allergenic potential of novel food proteins.
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Patel RK, Dodia MS, Joshi RH, Singh SP. Purification and characterization of alkaline protease from a newly isolated haloalkaliphilic Bacillus sp. Process Biochem 2006. [DOI: 10.1016/j.procbio.2006.04.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Yang R, Li SQ, Zhang QH. Effects of pulsed electric fields on the activity and structure of pepsin. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2004; 52:7400-7406. [PMID: 15563226 DOI: 10.1021/jf049183p] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A continuous pulsed electric field (PEF) system integrated with six co-field flow PEF treatment chambers was used to study the inactivation of pepsin. The inactivation of pepsin activity was a function of applied electric field strength, electrical conductivity, and pH. The inactivation of pepsin by PEF followed a first-order model. The first-order inactivation kinetic constant of pepsin was 0.012 (1/mus) in 7.5 mM HCl (pH 2.0) at 34.2 kV/cm. Aggregation of pepsin was observed during PEF treatment; however, the inactivation took place before the formation of aggregates. Circular dichroism analysis showed that inactivation of pepsin by PEF was correlated to the loss of beta-sheet structure in a pepsin molecule. The relative residual activity of PEF-treated pepsin was correlated to the relative molar ellipticity at 215 nm. Both PEF- and heat-induced inactivation of pepsin were correlated with the alteration of the secondary structure (beta-sheet dominant structure) of pepsin.
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Affiliation(s)
- Ruijin Yang
- Department of Food Science and Technology, 2015 Fyffe Road, The Ohio State University, Columbus, OH 43210, USA
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