1
|
Kumar V, Barwal A, Sharma N, Mir DS, Kumar P, Kumar V. Therapeutic proteins: developments, progress, challenges, and future perspectives. 3 Biotech 2024; 14:112. [PMID: 38510462 PMCID: PMC10948735 DOI: 10.1007/s13205-024-03958-z] [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: 06/03/2023] [Accepted: 02/13/2024] [Indexed: 03/22/2024] Open
Abstract
Proteins are considered magic molecules due to their enormous applications in the health sector. Over the past few decades, therapeutic proteins have emerged as a promising treatment option for various diseases, particularly cancer, cardiovascular disease, diabetes, and others. The formulation of protein-based therapies is a major area of research, however, a few factors still hinder the large-scale production of these therapeutic products, such as stability, heterogenicity, immunogenicity, high cost of production, etc. This review provides comprehensive information on various sources and production of therapeutic proteins. The review also summarizes the challenges currently faced by scientists while developing protein-based therapeutics, along with possible solutions. It can be concluded that these proteins can be used in combination with small molecular drugs to give synergistic benefits in the future.
Collapse
Affiliation(s)
- Vimal Kumar
- University Institute of Biotechnology, Chandigarh University, Gharuan, Mohali, Punjab 140413 India
| | - Arti Barwal
- Department of Microbial Biotechnology, Panjab University, South Campus, Sector-25, Chandigarh, 160014 India
| | - Nitin Sharma
- Department of Biotechnology, Chandigarh Group of Colleges, Mohali, Punjab 140307 India
| | - Danish Shafi Mir
- University Institute of Biotechnology, Chandigarh University, Gharuan, Mohali, Punjab 140413 India
| | - Pradeep Kumar
- Faculty of Applied Sciences and Biotechnology, Shoolini University of Biotechnology and Management Sciences, Solan, 173229 India
| | - Vikas Kumar
- University Institute of Biotechnology, Chandigarh University, Gharuan, Mohali, Punjab 140413 India
| |
Collapse
|
2
|
Yi Z, Chen L, Jin Y, Shen Y, Liu N, Fang Y, Xiao Y, Wang X, Peng K, He K, Zhao H. Insight into broad substrate specificity and synergistic contribution of a fungal α-glucosidase in Chinese Nong-flavor daqu. Microb Cell Fact 2023; 22:114. [PMID: 37322438 DOI: 10.1186/s12934-023-02124-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 06/07/2023] [Indexed: 06/17/2023] Open
Abstract
BACKGROUND Chinese Nong-favor daqu, the presentative liquor starter of Baijiu, has been enriched with huge amounts of enzymes in degrading various biological macromolecules by openly man-made process for thousand years. According to previous metatranscriptomics analysis, plenty of α-glucosidases were identified to be active in NF daqu and played the key role in degrading starch under solid-state fermentation. However, none of α-glucosidases was characterized from NF daqu, and their actual functions in NF daqu were still unknown. RESULTS An α-glucosidase (NFAg31A, GH31-1 subfamily), the second highest expressed α-glucosidases in starch degradation of NF daqu, was directly obtained by heterologous expression in Escherichia coli BL21 (DE3). NFAg31A exhibited the highest sequence identities of 65.8% with α-glucosidase II from Chaetomium thermophilum, indicating its origin of fungal species, and it showed some similar features with homologous α-glucosidase IIs, i.e., optimal activity at pH ~ 7.0 and litter higher temperature of 45 ℃, well stability at 41.3 ℃ and a broad pH range of pH 6.0 to pH 10.0, and preference on hydrolyzing Glc-α1,3-Glc. Besides this preference, NFAg31A showed comparable activities on Glc-α1,2-Glc and Glc-α1,4-Glc, and low activity on Glc-α1,6-Glc, indicating its broad specificities on α-glycosidic substrates. Additionally, its activity was not stimulated by any of those detected metal ions and chemicals, and could be largely inhibited by glucose under solid-state fermentation. Most importantly, it exhibited competent and synergistic effects with two characterized α-amylases of NF daqu on hydrolyzing starch, i.e., all of them could efficiently degrade starch and malto-saccharides, two α-amylases showed advantage in degrading starch and long-chain malto-saccharides, and NFAg31A played the competent role with α-amylases in degrading short-chain malto-saccharides and the irreplaceable contribution in hydrolyzing maltose into glucose, thus alleviating the product inhibitions of α-amylases. CONCLUSIONS This study provides not only a suitable α-glucosidase in strengthening the quality of daqu, but also an efficient way to reveal roles of the complicated enzyme system in traditional solid-state fermentation. This study would further stimulate more enzyme mining from NF daqu, and promote their actual applications in solid-state fermentation of NF liquor brewing, as well as in other solid-state fermentation of starchy industry in the future.
Collapse
Affiliation(s)
- Zhuolin Yi
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, 610041, P.R. China
| | - Lanchai Chen
- School of Food and Bioengineering, Xihua University, Chengdu, Sichuan, 610039, China
| | - Yanling Jin
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, 610041, P.R. China
| | - Yi Shen
- Sichuan Langjiu Co., Ltd, Gulin, 646523, China
| | - Nian Liu
- Sichuan Food and Fermentation Industry Research & Design Institute, Chengdu, 611130, China
| | - Yang Fang
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, 610041, P.R. China
| | - Yao Xiao
- Analytical and Testing Center, Sichuan University of Science and Engineering, Zigong, 643000, China
| | - Xi Wang
- Sichuan Langjiu Co., Ltd, Gulin, 646523, China
| | - Kui Peng
- Sichuan Food and Fermentation Industry Research & Design Institute, Chengdu, 611130, China
| | - Kaize He
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, 610041, P.R. China
| | - Hai Zhao
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, 610041, P.R. China.
| |
Collapse
|
3
|
Bhatia S, Batra N, Singh J. Production, purification, characterization, and applications of α-galactosidase from Bacillus flexus JS27 isolated from Manikaran hot springs. Prep Biochem Biotechnol 2022; 53:366-383. [PMID: 35801491 DOI: 10.1080/10826068.2022.2095572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
α-Galactosidase hydrolyzes the α-1,6-linkage present at the non-reducing end of the sugars and results in the release of galactosyl residue from oligosaccharides like melibiose, raffinose, stachyose, etc. In the present study we report, α-galactosidase from Bacillus flexus isolated from Manikaran hot springs (India). Maximum enzyme production was obtained in guar gum and soybean meal after 72 h at 150 rpm. While, the temperature/pH of production was optimized at 50 °C and 7.0, respectively. Isoenzymes (α-gal I and II) were obtained and characterized based on temperature/pH optima along with their stability profile. JS27 α-Gal II was purified with a final purification fold of 11.54. Native and SDS-PAGE were used to determine the molecular weight of the enzyme as 86 and 41 kDa, respectively, indicating its homodimeric form. JS27 α-Gal II showed optimum enzyme activity at 55 °C and pH 7 (10 min). The enzyme displayed Km value of 2.3809 mM and Vmax of 2.0 × 104 µmol/min/ml with pNPG as substrate. JS27 α-Gal II demonstrated substrate hydrolysis and simultaneous formation of transgalactosylation products (α-GOS) with numerous substrates (sugar/sugar alcohols, oligosaccharides, and complex carbohydrates) which were verified by TLC and HPLC analysis. α-GOS are significant functional food ingredients and can be explored as prebiotics.
Collapse
Affiliation(s)
- Sonu Bhatia
- Department of Biotechnology, Panjab University, Chandigarh, India.,Department of Biotechnology, Goswami Ganesh Dutta Sanatan Dharma College, Chandigarh, India
| | - Navneet Batra
- Department of Biotechnology, Goswami Ganesh Dutta Sanatan Dharma College, Chandigarh, India
| | - Jagtar Singh
- Department of Biotechnology, Panjab University, Chandigarh, India
| |
Collapse
|
4
|
Hu Y, Zhai L, Hong H, Shi Z, Zhao J, Liu D. Study on the Biochemical Characterization and Selectivity of Three β-Glucosidases From Bifidobacterium adolescentis ATCC15703. Front Microbiol 2022; 13:860014. [PMID: 35464910 PMCID: PMC9024363 DOI: 10.3389/fmicb.2022.860014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 02/16/2022] [Indexed: 11/22/2022] Open
Abstract
Three β-glucosidases from Bifidobacterium adolescentis ATCC15703, namely, BaBgl1A, BaBgl3A, and BaBgl3B, were overexpressed in Escherichia coli. The recombinant β-glucosidases were sufficiently purified using Ni2+ affinity chromatography, and BaBgl1A exhibited the best purification efficiency with a purification factor of 2.3-fold and specific activity of 71.2 U/mg. Three recombinant β-glucosidases acted on p-nitrophenyl-β-glucopyranoside (pNPβGlc) at around pH 7.0 and 30–50°C. The results of the substrate specificity assay suggested that BaBgl1A acted exclusively as β-1,2-glucosidase, while BaBgl3A and BaBgl3B acted mostly as β-1,3-glucosidase and β-1,4-glucosidase, respectively. The substrate specificity of the three recombinant enzymes was further studied using the ginsenosides Rb1 and Rd as substrates. The results of thin-layer chromatography and high-performance liquid chromatography analyses showed that BaBgl1A exhibited the highest bioconversion ability on Rb1 and Rd, where it hydrolyzed the outer C-3 glucose moieties of Rb1 and Rd into the rare ginsenosides Gypenoside XVII and F2; BaBgl3A exhibited medium bioconversion ability on Rb1, where it hydrolyzed both the outer C-3 and C-20 glucose moieties of Rb1 into Gyp XVII and Rd; and BaBgl3B was not active on Rb1 and Rd. These β-glucosidases will act as new biocatalytic tools for transforming ginsenosides and preparing active glycosides and aglycone.
Collapse
Affiliation(s)
- Yanbo Hu
- School of Food Science and Engineering, Changchun University, Changchun, China
| | - Liyuan Zhai
- School of Food Science and Engineering, Changchun University, Changchun, China
| | - Huili Hong
- School of Food Science and Engineering, Changchun University, Changchun, China
| | - Zenghui Shi
- School of Food Science and Engineering, Changchun University, Changchun, China
| | - Jun Zhao
- School of Food Science and Engineering, Changchun University, Changchun, China
- *Correspondence: Jun Zhao,
| | - Duo Liu
- School of Food Science and Engineering, Changchun University, Changchun, China
- School of Life Sciences, Changchun Normal University, Changchun, China
- Duo Liu,
| |
Collapse
|
5
|
Bhatia S, Singh A, Batra N, Singh J. Microbial production and biotechnological applications of α-galactosidase. Int J Biol Macromol 2019; 150:1294-1313. [PMID: 31747573 DOI: 10.1016/j.ijbiomac.2019.10.140] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 10/12/2019] [Accepted: 10/15/2019] [Indexed: 12/13/2022]
Abstract
α-Galactosidase, (E.C. 3.2.1.22) is an exoglycosidase that target galactooligosaccharides such as raffinose, melibiose, stachyose and branched polysaccharides like galactomannans and galacto-glucomannans by catalysing the hydrolysis of α-1,6 linked terminal galactose residues. The enzyme has been isolated and characterized from microbial, plant and animal sources. This ubiquitous enzyme possesses physiological significance and immense industrial potential. Optimization of the growth conditions and efficient purification strategies can lead to a significant increase in the enzyme production. To boost commercial productivity, cloning of novel α-galactosidase genes and their heterologous expression in suitable host has gained popularity. Enzyme immobilization leads to its greater reutilization, superior thermostability, pH tolerance and increased activity. The enzyme is well explored in food industry in the removal of raffinose family oligosaccharides (RFOs) in soymilk and sugar crystallization process. It also improves animal feed quality and biomass processing. Applications of the enzyme is in the area of biomedicine includes therapeutic advances in treatment of Fabry disease, blood group conversion and removal of α-gal type immunogenic epitopes in xenotransplantation. With considerable biotechnological applications, this enzyme has been vastly commercialized and holds greater future prospects.
Collapse
Affiliation(s)
- Sonu Bhatia
- Department of Biotechnology, Panjab University, Chandigarh, India
| | - Abhinashi Singh
- Department of Biotechnology, G.G.D.S.D. College, Sector-32-C, Chandigarh, India
| | - Navneet Batra
- Department of Biotechnology, G.G.D.S.D. College, Sector-32-C, Chandigarh, India
| | - Jagtar Singh
- Department of Biotechnology, Panjab University, Chandigarh, India.
| |
Collapse
|
6
|
Chaudet MM, Rose DR. Suggested alternative starch utilization system from the human gut bacterium Bacteroides thetaiotaomicron. Biochem Cell Biol 2016; 94:241-6. [PMID: 27093479 DOI: 10.1139/bcb-2016-0002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The human digestive system is host to a highly populated ecosystem of bacterial species that significantly contributes to our assimilation of dietary carbohydrates. Bacteroides thetaiotaomicron is a member of this ecosystem, and participates largely in the role of the gut microbiome by breaking down dietary complex carbohydrates. This process of acquiring glycans from the colon lumen is predicted to rely on the mechanisms of proteins that are part of a classified system known as polysaccharide utilization loci (PUL). These loci are responsible for binding substrates at the cell outer membrane, internalizing them, and then hydrolyzing them within the periplasm into simple sugars. Here we report our investigation into specific components of a PUL, and suggest an alternative starch utilization system in B. thetaiotaomicron. Our analysis of an outer membrane binding protein, a SusD homolog, highlights its contribution to this PUL by acquiring starch-based sugars from the colon lumen. Through our structural characterization of two Family GH31 α-glucosidases, we reveal the flexibility of this bacterium with respect to utilizing a range of starch-derived glycans with an emphasis on branched substrates. With these results we demonstrate the predicted function of a gene locus that is capable of contributing to starch hydrolysis in the human colon.
Collapse
Affiliation(s)
- Marcia M. Chaudet
- University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
- University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - David R. Rose
- University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
- University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| |
Collapse
|
7
|
Chaudet MM, Rose DR. Divergent evolution for diverse substrate recognition by family 31 glycoside hydrolases. Biochem Cell Biol 2016; 94:323-30. [PMID: 27459002 DOI: 10.1139/bcb-2016-0022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Carbohydrates make up an important component of our diet, contributing a significant portion to our total caloric intake. The ability to harvest these molecules for energy is reliant on the activity of carbohydrate-active enzymes. Family 31 α-glucosidases are a group of glycoside hydrolases that has been shown to play a key role in the metabolic process of hydrolyzing dietary starch into monomers of glucose. The purpose of the research presented here is to explore evolutionary changes that occurred within this family of glycoside hydrolases, and to relate these divergences to observed structural differences in relation to predicted substrate preferences. Here we report specific single amino acid changes that are believed to have arisen through evolution, and are directly related to the ability of these enzymes to bind different starch-based glycans. Through phylogenetic analysis we observed a number of evolutionary adaptions that we believe resulted in duplicated genes that allow for the efficient utilization of dietary starch.
Collapse
Affiliation(s)
- M M Chaudet
- University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada.,University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - D R Rose
- University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada.,University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| |
Collapse
|
8
|
He K, Zou Z, Hu Y, Yang Y, Xiao Y, Gao P, Li X, Ye X. Purification of α-glucosidase from mouse intestine by countercurrent chromatography coupled with a reverse micelle solvent system. J Sep Sci 2016; 39:703-8. [PMID: 26663433 DOI: 10.1002/jssc.201501092] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 11/30/2015] [Accepted: 12/03/2015] [Indexed: 11/08/2022]
Abstract
Countercurrent chromatography coupled with a reverse micelle solvent was applied to separate α-glucosidase, which is stable at pH 6.0-8.8, 15-50°C. The separation conditions are as follows: stationary phase: pH 4.0 Tris-HCl buffer phase containing 50 mM Tris-HCl and 50 mM KCl; mobile phase A: isooctane containing 50 mM anionic surfactant sodium di(2-ethylhexyl)sulfosuccinate; mobile phase B: 50 mM Tris-HCl buffer containing 500 mM KCl (pH 8.0); In total, 25 mL (23.9 mg) crude enzyme was injected through the injection valve, the enzymatic reaction and sodium dodecylsulfate polyacrylamide gel electrophoresis results imply that the activity of purified α-glucosidase is 6.63-fold higher than that of the crude enzyme. Therefore, countercurrent chromatography coupled with a reverse micelle solvent is capable for protein separation and enrichment.
Collapse
Affiliation(s)
- Kai He
- School of Pharmaceutical Sciences, Southwest University, Chongqing, China.,Department of Clinical Laboratory, Hunan University of Medicine, Hunan, China
| | - Zongyao Zou
- School of Pharmaceutical Sciences, Southwest University, Chongqing, China
| | - Yinran Hu
- School of Pharmaceutical Sciences, Southwest University, Chongqing, China
| | - Yong Yang
- Department of Clinical Laboratory, Hunan University of Medicine, Hunan, China
| | - Yubo Xiao
- School of Pharmaceutical Sciences, Southwest University, Chongqing, China.,Department of Clinical Laboratory, Hunan University of Medicine, Hunan, China
| | - Pincao Gao
- Department of Clinical Laboratory, Hunan University of Medicine, Hunan, China
| | - Xuegang Li
- School of Pharmaceutical Sciences, Southwest University, Chongqing, China
| | - Xiaoli Ye
- School of Life Sciences, Southwest University, Chongqing, China
| |
Collapse
|
9
|
Structural and biochemical characterization of novel bacterial α-galactosidases belonging to glycoside hydrolase family 31. Biochem J 2015; 469:145-58. [DOI: 10.1042/bj20150261] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 05/05/2015] [Indexed: 11/17/2022]
Abstract
We identified two bacterial enzymes as the first members that displayed α-galactosidase activity and the crystal structures provided insights into their novel substrate specificity. This is the first report of α-galactosidases which belong to the GH31 family.
Collapse
|
10
|
Piao H, Froula J, Du C, Kim TW, Hawley ER, Bauer S, Wang Z, Ivanova N, Clark DS, Klenk HP, Hess M. Identification of novel biomass-degrading enzymes from genomic dark matter: Populating genomic sequence space with functional annotation. Biotechnol Bioeng 2014; 111:1550-65. [PMID: 24728961 DOI: 10.1002/bit.25250] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Revised: 02/21/2014] [Accepted: 03/24/2014] [Indexed: 11/06/2022]
Abstract
Although recent nucleotide sequencing technologies have significantly enhanced our understanding of microbial genomes, the function of ∼35% of genes identified in a genome currently remains unknown. To improve the understanding of microbial genomes and consequently of microbial processes it will be crucial to assign a function to this "genomic dark matter." Due to the urgent need for additional carbohydrate-active enzymes for improved production of transportation fuels from lignocellulosic biomass, we screened the genomes of more than 5,500 microorganisms for hypothetical proteins that are located in the proximity of already known cellulases. We identified, synthesized and expressed a total of 17 putative cellulase genes with insufficient sequence similarity to currently known cellulases to be identified as such using traditional sequence annotation techniques that rely on significant sequence similarity. The recombinant proteins of the newly identified putative cellulases were subjected to enzymatic activity assays to verify their hydrolytic activity towards cellulose and lignocellulosic biomass. Eleven (65%) of the tested enzymes had significant activity towards at least one of the substrates. This high success rate highlights that a gene context-based approach can be used to assign function to genes that are otherwise categorized as "genomic dark matter" and to identify biomass-degrading enzymes that have little sequence similarity to already known cellulases. The ability to assign function to genes that have no related sequence representatives with functional annotation will be important to enhance our understanding of microbial processes and to identify microbial proteins for a wide range of applications.
Collapse
Affiliation(s)
- Hailan Piao
- School of Molecular Biosciences, Washington State University, Richland, Washington, 99352; Pacific Northwest National Laboratory, Richland, Washington
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Lactobacillus strains isolated from infant faeces possess potent inhibitory activity against intestinal alpha- and beta-glucosidases suggesting anti-diabetic potential. Eur J Nutr 2014; 53:1465-74. [PMID: 24414142 DOI: 10.1007/s00394-013-0649-9] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 12/27/2013] [Indexed: 12/22/2022]
Abstract
PURPOSE Inhibitors of intestinal alpha-glucosidases are used therapeutically to treat type 2 diabetes mellitus. Bacteria such as Actinoplanes sp. naturally produce potent alpha-glucosidase inhibitor compounds, including the most widely available drug acarbose. It is not known whether lactic acid bacteria (LAB) colonising the human gut possess inhibitory potential against glucosidases. Hence, the study was undertaken to screen LABs having inherent alpha- and beta-glucosidase inhibitory potential. METHODS This study isolated, screened, identified and extracted Lactobacillus strains (Lb1-15) from human infant faecal samples determining their inhibitory activity against intestinal maltase, sucrase, lactase and amylase. Lactobacillus reference strains (Ref1-7), a Gram positive control (Ctrl1) and two Gram negative controls (Ctrl2-3), were also analysed to compare activity. RESULTS Faecal isolates were identified by DNA sequencing, with the majority identified as unique strains of Lactobacillus plantarum. Some strains (L. plantarum, L. fermentum, L. casei and L. rhamnosus) had potent and broad spectrum inhibitory activities (up to 89%; p < 0.001; 500 mg/ml wet weight) comparable to acarbose (up to 88%; p < 0.001; 30 mg/ml). Inhibitory activity was concentration-dependent and was freely available in the supernatant, and was not present in other bacterial genera (Bifidobacterium bifidum and Escherichia coli or Salmonella typhimurium). Interestingly, the potency and spectrum of inhibitory activity across strains of a single species (L. plantarum) differed substantially. Some Lactobacillus extracts had broader spectrum activities than acarbose, effectively inhibiting beta-glucosidase activity (lactase) as well as alpha-glucosidase activities (maltase, sucrase and amylase). Anti-diabetic potential was indicated by the fact that oral gavage with a L. rhamnosus extract (1 g/kg) was able to reduce glucose excursions (Area under curve; 22%; p < 0.05) in rats during a carbohydrate challenge (starch; 2 g/kg). CONCLUSION These results definitively demonstrate that Lactobacillus strains present in the human gut have alpha- and beta-glucosidase inhibitory activities and can reduce blood glucose responses in vivo. Although the potential use of LAB such as Lactobacillus as a dietary supplement, medicinal food or biotherapeutic for diabetes is uncertain, such an approach might offer advantages over drug therapies in terms of broader spectrum activities and fewer unpleasant side effects. Further characterisation of this bioactivity is warranted, and chronic studies should be undertaken in appropriate animal models or diabetic subjects.
Collapse
|
12
|
Gao N, Shearwin K, Mack J, Finzi L, Dunlap D. Purification of bacteriophage lambda repressor. Protein Expr Purif 2013; 91:30-6. [PMID: 23831434 DOI: 10.1016/j.pep.2013.06.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 06/10/2013] [Accepted: 06/17/2013] [Indexed: 01/06/2023]
Abstract
Bacteriophage lambda repressor controls the lysogeny/lytic growth switch after infection of E. coli by lambda phage. In order to study in detail the looping of DNA mediated by the protein, tag-free repressor and a loss-of-cooperativity mutant were expressed in E.coli and purified by (1) ammonium sulfate fractionation, (2) anion-exchange chromatography and (3) heparin affinity chromatography. This method employs more recently developed and readily available chromatography resins to produce highly pure protein in good yield. In tethered particle motion looping assays and atomic force microscopy "footprinting" assays, both the wild-type protein and a C-terminal His-tagged variant, purified using immobilized metal affinity chromatography, bound specifically to high affinity sites to mediate loop formation. In contrast the G147D loss-of-cooperativity mutant bound specifically but did not secure loops.
Collapse
Affiliation(s)
- Ning Gao
- Physics Department, Emory University, 400 Dowman Dr., Atlanta, GA 30322, United States
| | | | | | | | | |
Collapse
|