1
|
Cho DH, Kim S, Lee Y, Shin Y, Choi S, Oh J, Kim HT, Park SH, Park K, Bhatia SK, Yang YH. Enhanced theanine production with reduced ATP supply by alginate entrapped Escherichia coli co-expressing γ-glutamylmethylamide synthetase and polyphosphate kinase. Enzyme Microb Technol 2024; 175:110394. [PMID: 38277867 DOI: 10.1016/j.enzmictec.2024.110394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/11/2024] [Accepted: 01/11/2024] [Indexed: 01/28/2024]
Abstract
L-theanine is an amino acid with a unique flavor and many therapeutic effects. Its enzymatic synthesis has been actively studied and γ-Glutamylmethylamide synthetase (GMAS) is one of the promising enzymes in the biological synthesis of theanine. However, the theanine biosynthetic pathway with GMAS is highly ATP-dependent and the supply of external ATP was needed to achieve high concentration of theanine production. As a result, this study aimed to investigate polyphosphate kinase 2 (PPK2) as ATP regeneration system with hexametaphosphate. Furthermore, the alginate entrapment method was employed to immobilize whole cells containing both gmas and ppk2 together resulting in enhanced reusability of the theanine production system with reduced supply of ATP. After immobilization, theanine production was increased to 239 mM (41.6 g/L) with a conversion rate of 79.7% using 15 mM ATP and the reusability was enhanced, maintaining a 100% conversion rate up to the fifth cycles and 60% of conversion up to eighth cycles. It could increase long-term storage property for future uses up to 35 days with 75% activity of initial activity. Overall, immobilization of both production and cofactor regeneration system could increase the stability and reusability of theanine production system.
Collapse
Affiliation(s)
- Do Hyun Cho
- Department of Biological Engineering, College of Engineering, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Suwon Kim
- Department of Biological Engineering, College of Engineering, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Yeda Lee
- Department of Biological Engineering, College of Engineering, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Yuni Shin
- Department of Biological Engineering, College of Engineering, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Suhye Choi
- Department of Biological Engineering, College of Engineering, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Jinok Oh
- Department of Biological Engineering, College of Engineering, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Hee Taek Kim
- Department of Food Science and Technology, Chungnam National University, Daejeon 34134, Republic of Korea
| | - See-Hyoung Park
- Department of Biological and Chemical Engineering, Hongik University, Sejong 30016, Republic of Korea
| | - Kyungmoon Park
- Department of Biological and Chemical Engineering, Hongik University, Sejong 30016, Republic of Korea
| | - Shashi Kant Bhatia
- Department of Biological Engineering, College of Engineering, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea; Institute for Ubiquitous Information Technology and Applications, Konkuk University, Seoul 05029, Republic of Korea
| | - Yung-Hun Yang
- Department of Biological Engineering, College of Engineering, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea; Institute for Ubiquitous Information Technology and Applications, Konkuk University, Seoul 05029, Republic of Korea.
| |
Collapse
|
2
|
Gautam LK, Sharma P, Capalash N. Structural insight into substrate binding of Acinetobacter baumannii polyphosphate-AMP phosphotransferase ( PPK2), a novel drug target. Biochem Biophys Res Commun 2022; 626:107-113. [PMID: 35987095 DOI: 10.1016/j.bbrc.2022.07.090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 07/23/2022] [Indexed: 11/02/2022]
Abstract
Acinetobacter baumannii is an opportunistic pathogen known for high morbidity and mortality. It causes life-threatening infections, such as ventilator-associated pneumonia (VAP), bacteremia, meningitis, wound and urinary tract infections (UTI). Increase in carbapenem resistance exhibited by A. baumannii has accentuated the need for novel targets for effective treatment. Despite the pronounced relevance of PPK2 as a pathogenicity determinant in several pathogens, it has not been explored as a drug target in A. baumannii. The present study was piloted to investigate the substrate binding by A. baumannii PPK2 (AbPPK2), a two-domain Class II polyphosphate kinase 2. A homology model of AbPPK2 was developed and validated for molecular docking of ATP and ADP in the predicted binding pocket. Further analysis of AbPPK2 revealed a set of common residues in the catalytic cleft interacting with ATP and ADP which would be useful for the screening of inhibitors against A. baumannii.
Collapse
Affiliation(s)
- Lalit Kumar Gautam
- Department of Biotechnology, Panjab University, BMS Block-I, Sector- 25, Chandigarh, 160014, India.
| | - Prince Sharma
- Department of Microbiology, Panjab University, BMS Block-I, Sector- 25, Chandigarh, 160014, India.
| | - Neena Capalash
- Department of Biotechnology, Panjab University, BMS Block-I, Sector- 25, Chandigarh, 160014, India.
| |
Collapse
|
3
|
Neville N, Roberge N, Jia Z. Polyphosphate Kinase 2 ( PPK2) Enzymes: Structure, Function, and Roles in Bacterial Physiology and Virulence. Int J Mol Sci 2022; 23:ijms23020670. [PMID: 35054854 PMCID: PMC8776046 DOI: 10.3390/ijms23020670] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 01/27/2023] Open
Abstract
Inorganic polyphosphate (polyP) has been implicated in an astonishing array of biological functions, ranging from phosphorus storage to molecular chaperone activity to bacterial virulence. In bacteria, polyP is synthesized by polyphosphate kinase (PPK) enzymes, which are broadly subdivided into two families: PPK1 and PPK2. While both enzyme families are capable of catalyzing polyP synthesis, PPK1s preferentially synthesize polyP from nucleoside triphosphates, and PPK2s preferentially consume polyP to phosphorylate nucleoside mono- or diphosphates. Importantly, many pathogenic bacteria such as Pseudomonas aeruginosa and Acinetobacter baumannii encode at least one of each PPK1 and PPK2, suggesting these enzymes may be attractive targets for antibacterial drugs. Although the majority of bacterial polyP studies to date have focused on PPK1s, PPK2 enzymes have also begun to emerge as important regulators of bacterial physiology and downstream virulence. In this review, we specifically examine the contributions of PPK2s to bacterial polyP homeostasis. Beginning with a survey of the structures and functions of biochemically characterized PPK2s, we summarize the roles of PPK2s in the bacterial cell, with a particular emphasis on virulence phenotypes. Furthermore, we outline recent progress on developing drugs that inhibit PPK2 enzymes and discuss this strategy as a novel means of combatting bacterial infections.
Collapse
|
4
|
Abstract
Polyphosphate (polyP) is a universally conserved molecule that plays critical roles in managing bacterial stress responses, in addition to biofilm formation and virulence. The enzymes that make polyphosphate molecules are called polyphosphate kinases (PPKs). Since these enzymes are not conserved in higher eukaryotes, PPKs make excellent therapeutic targets. In a recent paper in mBio, Neville and colleagues described gallein, a commercially available G-protein antagonist, as a novel dual-specificity inhibitor against two families of PPK enzymes in Pseudomonas aeruginosa. In this commentary, we discuss the impact of this discovery, outline potential challenges of implementing gallein use in the clinic, and describe how gallein will serve as a fantastic new tool to further fundamental PPK and polyP research in bacteria.
Collapse
|