1
|
Krishna de Guzman M, Stanic-Vucinic D, Gligorijevic N, Wimmer L, Gasparyan M, Lujic T, Vasovic T, Dailey LA, Van Haute S, Cirkovic Velickovic T. Small polystyrene microplastics interfere with the breakdown of milk proteins during static in vitro simulated human gastric digestion. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 335:122282. [PMID: 37516294 DOI: 10.1016/j.envpol.2023.122282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 07/12/2023] [Accepted: 07/27/2023] [Indexed: 07/31/2023]
Abstract
Human ingestion of microplastics (MPs) is common and inevitable due to the widespread contamination of food items, but implications on the gastric digestion of food proteins are still unknown. In this study, the interactions between pepsin and polystyrene (PS) MPs were evaluated by investigating enzyme activity and conformation in a simulated human gastric environment in the presence or absence of PS MPs. The impact on food digestion was also assessed by monitoring the kinetics of protein hydrolysis through static in vitro gastric digestion of cow's milk contaminated with PS. The binding of pepsin to PS showed that the surface chemistry of MPs dictates binding affinity. The key contributor to pepsin adsorption seems to be π-π interactions between the aromatic residues and the PS phenyl rings. During quick exposure (10 min) of pepsin to increasing concentrations (222, 2219, 22188 particles/mL) of 10 μm PS (PS10) and 100 μm PS (PS100), total enzymatic activities were not affected remarkably. However, upon prolonged exposure at 1 and 2 h, preferential binding of pepsin to the small, low zeta-potential PS caused structural changes in the protein which led to a significant reduction of its activity. Digestion of cow's milk mixed with PS10 resulted in transient accumulation of larger peptides (10-35 kDa) and reduced bioavailability of short peptides (2-9 kDa) in the gastric phase. This, however, was only observed at extremely high PS10 concentration (0.3 mg/mL or 5.46E+05 particles/mL). The digestion of milk peptides, bound preferentially over pepsin within the hard corona on the PS10 surface, was delayed up to 15 min in comparison to bulk protein digestion. Intact caseins, otherwise rapidly digested, remained bound to PS10 in the hard corona for up to 15 min. This work presents valuable insights regarding the interaction of MPs, food proteins, and pepsin, and their dynamics during gastric digestion.
Collapse
Affiliation(s)
- Maria Krishna de Guzman
- Department of Food Technology, Safety, and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium; Center for Food Chemistry and Technology, Ghent University Global Campus, Incheon, Republic of Korea
| | - Dragana Stanic-Vucinic
- Center of Excellence for Molecular Food Sciences, Department of Biochemistry, University of Belgrade - Faculty of Chemistry, Belgrade, Serbia
| | - Nikola Gligorijevic
- Department of Chemistry, University of Belgrade - Institute of Chemistry, Technology and Metallurgy, National Institute of Republic of Serbia, Belgrade, Serbia
| | - Lukas Wimmer
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Manvel Gasparyan
- Center for Biosystems and Biotech Data Science, Ghent University Global Campus, Republic of Korea; School of Environmental Engineering, University of Seoul, Seoul, Republic of Korea
| | - Tamara Lujic
- Center of Excellence for Molecular Food Sciences, Department of Biochemistry, University of Belgrade - Faculty of Chemistry, Belgrade, Serbia
| | - Tamara Vasovic
- Center of Excellence for Molecular Food Sciences, Department of Biochemistry, University of Belgrade - Faculty of Chemistry, Belgrade, Serbia
| | - Lea Ann Dailey
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Sam Van Haute
- Department of Food Technology, Safety, and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium; Center for Food Chemistry and Technology, Ghent University Global Campus, Incheon, Republic of Korea
| | - Tanja Cirkovic Velickovic
- Department of Food Technology, Safety, and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium; Center for Food Chemistry and Technology, Ghent University Global Campus, Incheon, Republic of Korea; Center of Excellence for Molecular Food Sciences, Department of Biochemistry, University of Belgrade - Faculty of Chemistry, Belgrade, Serbia; Serbian Academy of Sciences and Arts, Belgrade, Serbia.
| |
Collapse
|
2
|
Loredo‐Alejos JM, Lucio‐Porto R, Pavón LL, Moreno‐Cortez IE. Pepsin immobilization by electrospinning of poly(vinyl alcohol) nanofibers. J Appl Polym Sci 2022. [DOI: 10.1002/app.51700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Julia M. Loredo‐Alejos
- Fac. de Ingeniería Mecánica y Eléctrica (FIME) Universidad Autónoma de Nuevo Leon (UANL), Av. Universidad S/N San Nicolás de los Garza Nuevo León Mexico
- Centro de Innovación, Investigación y Desarrollo en Ingeniería y Tecnología (CIIDIT) Universidad Autónoma de Nuevo León (UANL) Apodaca Nuevo León Mexico
| | - Raul Lucio‐Porto
- Fac. de Ingeniería Mecánica y Eléctrica (FIME) Universidad Autónoma de Nuevo Leon (UANL), Av. Universidad S/N San Nicolás de los Garza Nuevo León Mexico
- Centro de Innovación, Investigación y Desarrollo en Ingeniería y Tecnología (CIIDIT) Universidad Autónoma de Nuevo León (UANL) Apodaca Nuevo León Mexico
| | - Luis Lopez Pavón
- Fac. de Ingeniería Mecánica y Eléctrica (FIME) Universidad Autónoma de Nuevo Leon (UANL), Av. Universidad S/N San Nicolás de los Garza Nuevo León Mexico
- Centro de Innovación, Investigación y Desarrollo en Ingeniería y Tecnología (CIIDIT) Universidad Autónoma de Nuevo León (UANL) Apodaca Nuevo León Mexico
| | - Ivan E. Moreno‐Cortez
- Fac. de Ingeniería Mecánica y Eléctrica (FIME) Universidad Autónoma de Nuevo Leon (UANL), Av. Universidad S/N San Nicolás de los Garza Nuevo León Mexico
- Centro de Innovación, Investigación y Desarrollo en Ingeniería y Tecnología (CIIDIT) Universidad Autónoma de Nuevo León (UANL) Apodaca Nuevo León Mexico
| |
Collapse
|
3
|
Li TJ, Wen BY, Ma XH, Huang WT, Wu JZ, Lin XM, Zhang YJ, Li JF. Rapid and Simple Analysis of the Human Pepsin Secondary Structure Using a Portable Raman Spectrometer. Anal Chem 2021; 94:1318-1324. [PMID: 34928126 DOI: 10.1021/acs.analchem.1c04531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Human pepsin is a digestive protease that plays an important role in the human digestive system. The secondary structure of human pepsin determines its bioactivity. Therefore, an in-depth understanding of human pepsin secondary structure changes is particularly important for the further improvement of the efficiency of human pepsin biological function. However, the complexity and diversity of the human pepsin secondary structure make its analysis difficult. Herein, a convenient method has been developed to quickly detect the secondary structure of human pepsin using a portable Raman spectrometer. According to the change of surface-enhanced Raman spectroscopy (SERS) signal intensity and activity of human pepsin at different pH values, we analyze the change of the human pepsin secondary structure. The results show that the content of the β-sheet gradually increased with the increase in the pH in the active range, which is in good agreement with circular dichroism (CD) measurements. The change of the secondary structure improves the sensitivity of human pepsin SERS detection. Meanwhile, human pepsin is a commonly used disease marker for the noninvasive diagnosis of gastroesophageal reflux disease (GERD); the detection limit of human pepsin we obtained is 2 μg/mL by the abovementioned method. The real clinical detection scenario is also simulated by spiking pepsin solution in saliva, and the standard recovery rate is 80.7-92.3%. These results show the great prospect of our method in studying the protein secondary structure and furthermore promote the application of SERS in clinical diagnosis.
Collapse
Affiliation(s)
- Tong-Jiang Li
- Women and Children's Hospital Affiliated to Xiamen University, School of medicine, College of Chemistry and Chemical Engineering, College of Energy, Xiamen University, Xiamen 361005, China
| | - Bao-Ying Wen
- Women and Children's Hospital Affiliated to Xiamen University, School of medicine, College of Chemistry and Chemical Engineering, College of Energy, Xiamen University, Xiamen 361005, China
| | - Xiao-Hui Ma
- Women and Children's Hospital Affiliated to Xiamen University, School of medicine, College of Chemistry and Chemical Engineering, College of Energy, Xiamen University, Xiamen 361005, China
| | - Wan-Ting Huang
- Women and Children's Hospital Affiliated to Xiamen University, School of medicine, College of Chemistry and Chemical Engineering, College of Energy, Xiamen University, Xiamen 361005, China
| | - Jin-Zhun Wu
- Women and Children's Hospital Affiliated to Xiamen University, School of medicine, College of Chemistry and Chemical Engineering, College of Energy, Xiamen University, Xiamen 361005, China
| | - Xiu-Mei Lin
- Women and Children's Hospital Affiliated to Xiamen University, School of medicine, College of Chemistry and Chemical Engineering, College of Energy, Xiamen University, Xiamen 361005, China
| | - Yue-Jiao Zhang
- Women and Children's Hospital Affiliated to Xiamen University, School of medicine, College of Chemistry and Chemical Engineering, College of Energy, Xiamen University, Xiamen 361005, China
| | - Jian-Feng Li
- Women and Children's Hospital Affiliated to Xiamen University, School of medicine, College of Chemistry and Chemical Engineering, College of Energy, Xiamen University, Xiamen 361005, China
| |
Collapse
|
4
|
Sun M, Wei X, Wang H, Xu C, Wei B, Zhang J, He L, Xu Y, Li S. Structure Restoration of Thermally Denatured Collagen by Ultrahigh Pressure Treatment. FOOD BIOPROCESS TECH 2019. [DOI: 10.1007/s11947-019-02389-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
5
|
Biter AB, Pollet J, Chen WH, Strych U, Hotez PJ, Bottazzi ME. A method to probe protein structure from UV absorbance spectra. Anal Biochem 2019; 587:113450. [DOI: 10.1016/j.ab.2019.113450] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 09/19/2019] [Accepted: 09/20/2019] [Indexed: 01/15/2023]
|
6
|
Leite Júnior BRDC, Tribst AAL, Grant NJ, Yada RY, Cristianini M. Biophysical evaluation of milk-clotting enzymes processed by high pressure. Food Res Int 2017; 97:116-122. [PMID: 28578031 DOI: 10.1016/j.foodres.2017.03.042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 03/23/2017] [Accepted: 03/23/2017] [Indexed: 10/19/2022]
Abstract
High pressure processing (HPP) is able to promote changes in enzymes structure. This study evaluated the effect of HP on the structural changes in milk-clotting enzymes processed under activation conditions for recombinant camel chymosin (212MPa/5min/10°C), calf rennet (280MPa/20min/25°C), bovine rennet (222MPa/5min/23°C), and porcine pepsin (50MPa/5min/20°C) and under inactivation conditions for all enzymes (600MPa/10min/25°C) including the protease from Rhizomucor miehei. In general, it was found that the HPP at activation conditions was able to increase the intrinsic fluorescence of samples with high pepsin concentration (porcine pepsin and bovine rennet), increase significantly the surface hydrophobicity and induce changes in secondary structure of all enzymes. Under inactivation conditions, increases in surface hydrophobicity and a reduction of intrinsic fluorescence were observed, suggesting a higher exposure of hydrophobic sites followed by water quenching of Trp residues. Moreover, changes in secondary structure were observed (with minor changes seen in Rhizomucor miehei protease). In conclusion, HPP was able to unfold milk-clotting enzymes even under activation conditions, and the porcine pepsin and bovine rennet were more sensitive to HPP.
Collapse
Affiliation(s)
- Bruno Ricardo de Castro Leite Júnior
- Department of Food Technology (DTA), School of Food Engineering (FEA), University of Campinas (UNICAMP), Monteiro Lobato, 80. PO Box 6121, 13083-862 Campinas, SP, Brazil
| | - Alline Artigiani Lima Tribst
- Center of Studies and Researches in Food (NEPA), University of Campinas (UNICAMP), Albert Einstein, 291, 13083-852 Campinas, SP, Brazil
| | - Nicholas J Grant
- Faculty of Land and Food Systems, The University of British Columbia (UBC), MacMillan Building 248, 2357 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Rickey Y Yada
- Faculty of Land and Food Systems, The University of British Columbia (UBC), MacMillan Building 248, 2357 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Marcelo Cristianini
- Department of Food Technology (DTA), School of Food Engineering (FEA), University of Campinas (UNICAMP), Monteiro Lobato, 80. PO Box 6121, 13083-862 Campinas, SP, Brazil.
| |
Collapse
|
7
|
The prosegment catalyzes native folding of Plasmodium falciparum plasmepsin II. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:1356-62. [DOI: 10.1016/j.bbapap.2016.06.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/29/2016] [Accepted: 06/30/2016] [Indexed: 01/15/2023]
|
8
|
Biter AB, de la Peña AH, Thapar R, Lin JZ, Phillips KJ. DSF Guided Refolding As A Novel Method Of Protein Production. Sci Rep 2016; 6:18906. [PMID: 26783150 PMCID: PMC4726114 DOI: 10.1038/srep18906] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 09/29/2015] [Indexed: 02/04/2023] Open
Abstract
The Anfinsen hypothesis, the demonstration of which led to the Nobel prize in Chemistry, posits that all information required to determine a proteins’ three dimensional structure is contained within its amino acid sequence. This suggests that it should be possible, in theory, to fold any protein in vitro. In practice, however, protein production by refolding is challenging because suitable refolding conditions must be empirically determined for each protein and can be painstaking. Here we demonstrate, using a variety of proteins, that differential scanning fluorimetry (DSF) can be used to determine and optimize conditions that favor proper protein folding in a rapid and high-throughput fashion. The resulting method, which we deem DSF guided refolding (DGR), thus enables the production of aggregation-prone and disulfide-containing proteins by refolding from E. coli inclusion bodies, which would not normally be amenable to production in bacteria.
Collapse
Affiliation(s)
- Amadeo B Biter
- Diabetes and Metabolic Disease Program, Houston Methodist Research Institute, Houston, Texas, USA
| | - Andres H de la Peña
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Roopa Thapar
- Department of BioSciences-Biochemistry and Cell Biology, Rice University, Houston, Texas, USA
| | - Jean Z Lin
- Diabetes and Metabolic Disease Program, Houston Methodist Research Institute, Houston, Texas, USA
| | - Kevin J Phillips
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
| |
Collapse
|
9
|
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.
Collapse
|
10
|
The influence of protein fractions from bovine colostrum digested in vivo and in vitro on human intestinal epithelial cell proliferation. J DAIRY RES 2014; 81:73-81. [PMID: 24433585 DOI: 10.1017/s0022029913000654] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Colostrum consists of a number of biologically active proteins and peptides that influence physiological function and development of a neonate. The present study investigated the biological activity of peptides released from first day bovine colostrum through in vitro and in vivo enzymatic digestion. This was assessed for proliferative activity using a human intestinal epithelial cell line, T84. Digestion of the protein fraction of bovine colostrum in vitro was conducted with the enzymes pepsin, chymosin and trypsin. Pepsin and chymosin digests yielded protein fractions with proliferative activity similar to that observed with undigested colostrum and the positive control foetal calf serum (FCS). In contrast trypsin digestion significantly (P<0·05) decreased colostral proliferative activity when co-cultured with cells when compared with undigested colostrum. The proliferative activity of undigested colostrum protein and abomasal whey protein digesta significantly increased (P<0·05) epithelial cell proliferation in comparison to a synthetic peptide mix. Bovine colostrum protein digested in vivo was collected from different regions of the gastrointestinal tract (GIT) in newborn calves fed either once (n=3 calves) or three times at 12-h intervals (n=3 calves). Digesta collected from the distal duodenum, jejunum and colon of calves fed once, significantly (P<0·05) stimulated cell proliferation in comparison with comparable samples collected from calves fed multiple times. These peptide enriched fractions are likely to yield candidate peptides with potential application for gastrointestinal repair in mammalian species.
Collapse
|
11
|
Dee DR, Horimoto Y, Yada RY. Conserved prosegment residues stabilize a late-stage folding transition state of pepsin independently of ground states. PLoS One 2014; 9:e101339. [PMID: 24983988 PMCID: PMC4077824 DOI: 10.1371/journal.pone.0101339] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 06/05/2014] [Indexed: 11/24/2022] Open
Abstract
The native folding of certain zymogen-derived enzymes is completely dependent upon a prosegment domain to stabilize the folding transition state, thereby catalyzing the folding reaction. Generally little is known about how the prosegment accomplishes this task. It was previously shown that the prosegment catalyzes a late-stage folding transition between a stable misfolded state and the native state of pepsin. In this study, the contributions of specific prosegment residues to catalyzing pepsin folding were investigated by introducing individual Ala substitutions and measuring the effects on the bimolecular folding reaction between the prosegment peptide and pepsin. The effects of mutations on the free energies of the individual misfolded and native ground states and the transition state were compared using measurements of prosegment-pepsin binding and folding kinetics. Five out of the seven prosegment residues examined yielded relatively large kinetic effects and minimal ground state perturbations upon mutation, findings which indicate that these residues form strengthened and/or non-native contacts in the transition state. These five residues are semi- to strictly conserved, while only a non-conserved residue had no kinetic effect. One conserved residue was shown to form native structure in the transition state. These results indicated that the prosegment, which is only 44 residues long, has evolved a high density of contacts that preferentially stabilize the folding transition state over the ground states. It is postulated that the prosegment forms extensive non-native contacts during the process of catalyzing correct inter- and intra-domain contacts during the final stages of folding. These results have implications for understanding the folding of multi-domain proteins and for the evolution of prosegment-catalyzed folding.
Collapse
Affiliation(s)
- Derek R. Dee
- Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
| | - Yasumi Horimoto
- Department of Food Science, University of Guelph, Guelph, Ontario, Canada
| | - Rickey Y. Yada
- Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
- Department of Food Science, University of Guelph, Guelph, Ontario, Canada
- * E-mail:
| |
Collapse
|
12
|
Horimoto Y, Wang S, Yada RY. ¹H, ¹³C, and ¹⁵N backbone resonance assignments of the porcine pepsin and porcine pepsin complexed with pepstatin. BIOMOLECULAR NMR ASSIGNMENTS 2014; 8:57-61. [PMID: 23264006 DOI: 10.1007/s12104-012-9452-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 12/10/2012] [Indexed: 06/01/2023]
Abstract
Pepsin is formed as the zymogen, pepsinogen, which includes an additional 44 residue prosegment (PS) on the N-terminus. Upon acidification (pH <3) the PS is removed, yielding active pepsin. The PS is critical to such processes as the initiation of correct folding and protein stability. In the present study, the NMR assignments of the 34.6 kDa native porcine pepsin and porcine pepsin complexed with pepstatin are reported in order to obtain structural information regarding PS-catalyzed protein folding. Such information would contribute to a better understanding of the nature of folding/unfolding energy barrier of pepsin and other aspartic proteases.
Collapse
Affiliation(s)
- Yasumi Horimoto
- Department of Food Science, University of Guelph, Guelph, ON, N1G 2W1, Canada,
| | | | | |
Collapse
|
13
|
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.
Collapse
|
14
|
Luo K, Nie F, Yan Y, Wang S, Zheng X, Song Z. Study of captopril pharmacokinetics in rabbit blood with microdialysis based on online generated Au nanoclusters and pepsin–captopril interaction in luminol chemiluminescence. RSC Adv 2014. [DOI: 10.1039/c4ra09064k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A luminol–HAuCl4–pepsin (Pep) flow injection-chemiluminescence system was explored to determine captopril (CAP) based on the CL intensity inhibition effect and applied to study CAP pharmacokinetics in rabbits with microdialysis.
Collapse
Affiliation(s)
- Kai Luo
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education
- College of Chemistry & Material Science
- Northwest University
- Xi’an, China
| | - Fei Nie
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education
- College of Chemistry & Material Science
- Northwest University
- Xi’an, China
| | - Yumei Yan
- Key Laboratory of Resource Biology and Biotechnology in Western China
- College of Life Sciences
- Northwest University
- Xi’an, China
| | - Shixiang Wang
- Key Laboratory of Resource Biology and Biotechnology in Western China
- College of Life Sciences
- Northwest University
- Xi’an, China
| | - Xiaohui Zheng
- Key Laboratory of Resource Biology and Biotechnology in Western China
- College of Life Sciences
- Northwest University
- Xi’an, China
| | - Zhenghua Song
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education
- College of Chemistry & Material Science
- Northwest University
- Xi’an, China
| |
Collapse
|
15
|
Dee DR, Myers B, Yada RY. Dynamics of thermodynamically stable, kinetically trapped, and inhibitor-bound states of pepsin. Biophys J 2012; 101:1699-709. [PMID: 21961596 DOI: 10.1016/j.bpj.2011.08.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 07/19/2011] [Accepted: 08/01/2011] [Indexed: 11/17/2022] Open
Abstract
The pepsin folding mechanism involves a prosegment (PS) domain that catalyzes folding, which is then removed, resulting in a kinetically trapped native state. Although native pepsin (Np) is kinetically stable, it is irreversibly denatured due to a large folding barrier, and in the absence of the PS it folds to a more thermodynamically stable denatured state, termed refolded pepsin (Rp). This system serves as a model to understand the nature of kinetic barriers and folding transitions between compact states. Quasielastic neutron scattering (QENS) was used to characterize and compare the flexibility of Np, as a kinetically trapped state, with that of Rp, as a thermodynamically stable fold. Additionally, the dynamics of Np were compared with those of a partially unfolded form and a thermally stabilized, inhibitor-bound form. QENS revealed length-scale-dependent differences between Np and Rp on a picosecond timescale and indicated greater flexibility in Np, leading to the conclusion that kinetic stabilization likely does not correspond to reduced internal dynamics. Furthermore, large differences were observed upon inhibition, indicating that QENS of proteins in solution may prove useful for examining the role of conformational entropy changes in ligand binding.
Collapse
Affiliation(s)
- Derek R Dee
- Biophysics Interdepartmental Group, University of Guelph, Ontario, Canada
| | | | | |
Collapse
|
16
|
Xiao H, Dee D, Yada RY. The native conformation of plasmepsin II is kinetically trapped at neutral pH. Arch Biochem Biophys 2011; 513:102-9. [PMID: 21767524 DOI: 10.1016/j.abb.2011.06.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 06/29/2011] [Accepted: 06/30/2011] [Indexed: 10/18/2022]
Abstract
Plasmepsin II (PMII), an aspartic protease from the malarial parasite Plasmodium falciparum, represents a model for understanding protease structure/function relationships due to its unique structure and properties. The present study undertook a thermodynamic and kinetic analysis of the PMII folding mechanism and a pH stability profile. Differential scanning calorimetry revealed that the native state of PMII (Np) was irreversibly unfolded, and in the pH range of 6.5-8.0, PMII refolds to a denatured state (Rp) with higher thermal stability than Np. Rp could also be formed upon partially unfolding PMII at pH 11.0 and 37 °C for 2h, followed by adjustment to a pH in the range of 6.5-8.0. While Rp could be folded/unfolded reversibly, Np was shown to exist as a kinetically trapped state. By examining the unfolding kinetics of Np and the kinetics of Rp folding to Np at 25 °C, it was found that Np is kinetically trapped by an unfolding barrier of 25.5 kcal/mol, and yet once unfolded, is prevented from folding by a comparable folding barrier. The folding mechanism of PMII is similar to that reported for pepsin. It is hypothesized that the PMII zymogen also utilizes a prosegment-catalyzed folding mechanism.
Collapse
Affiliation(s)
- Huogen Xiao
- Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G2W1
| | | | | |
Collapse
|
17
|
Bryksa BC, Horimoto Y, Yada RY. Rational redesign of porcine pepsinogen containing an antimicrobial peptide. Protein Eng Des Sel 2010; 23:711-9. [PMID: 20601363 DOI: 10.1093/protein/gzq039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A novel strategy for the controlled release and localization of bioactive peptides within digestive and immunity-related enzymes was developed. The N-terminus of porcine pepsinogen A was fused to the basic amino acid-rich region of bovine lactoferricin B termed 'tLfcB', a cationic antimicrobial/anticancer peptide. Recombinant tLfcB-porcine pepsinogen A was expressed in soluble form in Escherichia coli as a thioredoxin (Trx) fusion protein. Thioredoxin-tLfcB-porcine pepsinogen A was found to activate autocatalytically under acidic conditions. Recombinant pepsin A derived from the activation of the fusion protein had a catalytic rate and substrate affinity similar to that derived from the recombinant thioredoxin-porcine pepsinogen A control. Pepsin-treated thioredoxin-tLfcB-porcine pepsinogen A yielded increased antimicrobial activity against the Gram-negative bacteria E.coli relative to control suggesting that a second function (antimicrobial activity) was successfully engineered into a functional peptidase. The novel design strategy described herein presents a potential strategy for targeted delivery of antimicrobial or therapeutic peptides in transgenic organisms via re-engineering native proteins critical to plant and animal defense mechanisms.
Collapse
Affiliation(s)
- Brian C Bryksa
- Department of Food Science, University of Guelph, Guelph, ON, Canada N1G 2W1
| | | | | |
Collapse
|
18
|
Giussani L, Fois E, Gianotti E, Tabacchi G, Gamba A, Coluccia S. On the Compatibility Criteria for Protein Encapsulation inside Mesoporous Materials. Chemphyschem 2010; 11:1757-62. [DOI: 10.1002/cphc.200901038] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
19
|
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.
Collapse
Affiliation(s)
- Derek R Dee
- Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada N1G 2W1
| | | |
Collapse
|
20
|
Sayer JM, Louis JM. Interactions of different inhibitors with active-site aspartyl residues of HIV-1 protease and possible relevance to pepsin. Proteins 2009; 75:556-68. [PMID: 18951411 DOI: 10.1002/prot.22271] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The importance of the active site region aspartyl residues 25 and 29 of the mature HIV-1 protease (PR) for the binding of five clinical and three experimental protease inhibitors [symmetric cyclic urea inhibitor DMP323, nonhydrolyzable substrate analog (RPB) and the generic aspartic protease inhibitor acetyl-pepstatin (Ac-PEP)] was assessed by differential scanning calorimetry. DeltaT(m) values, defined as the difference in T(m) for a given protein in the presence and absence of inhibitor, for PR with DRV, ATV, SQV, RTV, APV, DMP323, RPB, and Ac-PEP are 22.4, 20.8, 19.3, 15.6, 14.3, 14.7, 8.7, and 6.5 degrees C, respectively. Binding of APV and Ac-PEP is most sensitive to the D25N mutation, as shown by DeltaT(m) ratios [DeltaT(m)(PR)/DeltaT(m)(PR(D25N))] of 35.8 and 16.3, respectively, whereas binding of DMP323 and RPB (DeltaT(m) ratios of 1-2) is least affected. Binding of the substrate-like inhibitors RPB and Ac-PEP is nearly abolished (DeltaT(m)(PR)/DeltaT(m)(PR(D29N)) > or = 44) by the D29N mutation, whereas this mutation only moderately affects binding of the smaller inhibitors (DeltaT(m) ratios of 1.4-2.2). Of the nine FDA-approved clinical HIV-1 protease inhibitors screened, APV, RTV, and DRV competitively inhibit porcine pepsin with K(i) values of 0.3, 0.6, and 2.14 microM, respectively. DSC results were consistent with this relatively weak binding of APV (DeltaT(m) 2.7 degrees C) compared with the tight binding of Ac-PEP (DeltaT(m) > or = 17 degrees C). Comparison of superimposed structures of the PR/APV complex with those of PR/Ac-PEP and pepsin/pepstatin A complexes suggests a role for Asp215, Asp32, and Ser219 in pepsin, equivalent to Asp25, Asp25', and Asp29 in PR in the binding and stabilization of the pepsin/APV complex.
Collapse
Affiliation(s)
- Jane M Sayer
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, DHHS, Bethesda, MD 20892-0520, USA
| | | |
Collapse
|
21
|
Recombinant prosegment peptide acts as a folding catalyst and inhibitor of native pepsin. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2009; 1794:1795-801. [PMID: 19715777 DOI: 10.1016/j.bbapap.2009.08.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 08/16/2009] [Accepted: 08/18/2009] [Indexed: 11/23/2022]
Abstract
Porcine pepsin A, a gastric aspartic peptidase, is initially produced as the zymogen pepsinogen that contains an N-terminal, 44 residue prosegment (PS) domain. In the absence of the PS, native pepsin (Np) is irreversibly denatured and when placed under refolding conditions, folds to a thermodynamically stable denatured state. This denatured, refolded pepsin (Rp) state can be converted to Np by the exogenous addition of the PS, which catalyzes the folding of Rp to Np. In order to thoroughly study the mechanism by which the PS catalyzes pepsin folding, a soluble protein expression system was developed to produce recombinant PS peptide in a highly pure form. Using this system, the wild-type and three-mutant PS forms, in which single residue substitutions were made (V4A, R8A and K36A), were expressed and purified. These PS peptides were characterized for their ability to inhibit Np enzymatic activity and to catalyze the folding of Rp to Np. The V4A, R8A and K36A mutant PS peptides were found to have nanomolar inhibition constants, Ki, of 82.4, 58.3 and 95.6 nM, respectively, approximately a two-fold increase from that of the wild-type PS (36.2 nM). All three-mutant PS peptides were found to catalyze Np folding with a rate constant of 0.06 min(-1), five-fold lower than that of the wild-type. The observation that the mutant PS peptides retained their inhibition and folding-catalyst functionality suggests a high level of resilience to mutations of the pepsin PS.
Collapse
|
22
|
Sarmento AC, Oliveira CS, Pereira A, Esteves VI, Moir AJ, Saraiva J, Pires E, Barros M. Unfolding of cardosin A in organic solvents and detection of intermediaries. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.molcatb.2008.08.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
23
|
Abstract
The structure-function relationships of aspartic peptidases (APs) (EC 3.4.23.X) have been extensively investigated, yet much remains to be elucidated regarding the various molecular mechanisms of these enzymes. Over the past years, APs have received considerable interest for food applications (e.g. cheese, fermented foods) and as potential targets for pharmaceutical intervention in human diseases including hypertension, cancer, Alzheimer's disease, AIDS (acquired immune deficiency syndrome), and malaria. A deeper understanding of the structure and function of APs, therefore, will have a direct impact on the design of peptidase inhibitors developed to treat such diseases. Most APs are synthesized as zymogens which contain an N-terminal prosegment (PS) domain that is removed at acidic pH by proteolytic cleavage resulting in the active enzyme. While the nature of the AP PS function is not entirely understood, the PS can be important in processes such as the initiation of correct folding, protein stability, blockage of the active site, pH-dependence of activation, and intracellular sorting of the zymogen. This review summarizes the current knowledge of AP PS function (especially within the A1 family), with particular emphasis on protein folding, cellular sorting, and inhibition.
Collapse
|