1
|
Chen Y, Betenbaugh MJ. Reconstruction of reverse transsulfuration pathway enables cysteine biosynthesis and enhances resilience to oxidative stress in Chinese Hamster Ovary cells. Metab Eng 2023; 76:204-214. [PMID: 36822463 DOI: 10.1016/j.ymben.2023.02.010] [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: 04/08/2022] [Revised: 12/26/2022] [Accepted: 02/20/2023] [Indexed: 02/25/2023]
Abstract
Cysteine is a critically important amino acid necessary for mammalian cell culture, playing key roles in nutrient supply, disulfide bond formation, and as a precursor to antioxidant molecules controlling cellular redox. Unfortunately, its low stability and solubility in solution make it especially problematic as an essential medium component that must be added to Chinese hamster ovary and other mammalian cell cultures. Therefore, CHO cells have been engineered to include the capacity of endogenously synthesizing cysteine by overexpressing multiple enzymes, including cystathionine beta-synthase (CBS), cystathionine gamma-lyase (CTH) and glycine N-methyltransferase (GNMT) to reconstruct the reverse transsulfuration pathway and overcome a key metabolic bottleneck. Some limited cysteine biosynthesis was obtained by overexpressing CBS and CTH for converting homocysteine to cysteine but robust metabolic synthesis from methionine was only possibly after incorporating GNMT which likely represents a key bottleneck step in the cysteine biosynthesis pathway. CHO cells with the reconstructed pathway exhibit the strong capability to proliferate in cysteine-limited and cysteine-free batch and fed-batch cultures at levels comparable to wildtype cells with ample cysteine supplementation, providing a selectable marker for CHO cell engineering. GNMT overexpression led to the accumulation of sarcosine byproduct, but its accumulation did not affect cell growth. Furthermore, pathway reconstruction enhanced CHO cells' reduced and glutathione levels in cysteine-limited conditions compared to unmodified cells, and greatly enhanced survivability and maintenance of redox homeostasis under oxidative stress induced by addition of menadione in cysteine-deficient conditions. Such engineered CHO cell lines can potentially reduce or even eliminate the need to include cysteine in culture medium, which not only reduces the cost of mammalian media but also promises to transform media design by solving the challenges posed by low stability and solubility of cysteine and cystine in future mammalian biomanufacturing processes.
Collapse
Affiliation(s)
- Yiqun Chen
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Michael J Betenbaugh
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA.
| |
Collapse
|
2
|
Umair S, Bouchet C, Palevich N, Simpson HV. Characterisation and structural analysis of glyoxylate cycle enzymes of Teladorsagia circumcincta. Mol Biochem Parasitol 2020; 240:111335. [PMID: 33058935 DOI: 10.1016/j.molbiopara.2020.111335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/22/2020] [Accepted: 10/06/2020] [Indexed: 10/23/2022]
Abstract
A 1332 bp full length cDNA encoding Teladorsagia circumcincta isocitrate lyase (TciICL) and a 1575 bp full length cDNA encoding T. circumcincta malate synthase (TciMS) were cloned, expressed in Escherichia coli and the recombinant proteins purified. The predicted TciICL protein of 444 amino acids was present as a single band of about 52 kDa on SDS-PAGE and the recombinant TciMS of 525 amino acids formed a single band about 62 kDa. Multiple alignments of the combined bifunctional TciICL-MS protein sequence with homologues from other nematodes showed that the greatest similarity (89-92 %) to the homologues of Ancylostoma ceylanicum, Haemonchus contortus and Haemonchus placei and 71-87 % similarity to the other nematode sequences. The 3-dimensional structures, binding and catalytic sites were determined for TciICL and TciMS and shown to be highly conserved. Substrate and metal ion binding sites were identified and were completely conserved in other homologues. TciICL was confirmed as a functional enzyme. At 30 °C, the optimum pH was pH 7.5, the Vmax was 275 ± 23 nmoles.min-1. mg-1 protein and the apparent Km for the substrate isocitrate was 0.7 ± 0.01μM (mean ± SEM, n = 3). Addition of 10 mM metal ions (except Mg2+) or 1 mM inhibitors reduced the recombinant TciICL activity by 60-90 %. Antibodies in both serum and saliva from field-immune, but not nematode-naïve, sheep recognised recombinant TciICL in ELISA, supporting similar antigenicity to that of the native enzyme.
Collapse
Affiliation(s)
- Saleh Umair
- AgResearch Ltd, Private Bag 11-008, Palmerston North, New Zealand.
| | | | - Nikola Palevich
- AgResearch Ltd, Private Bag 11-008, Palmerston North, New Zealand
| | - Heather V Simpson
- School of Veterinary Science, Massey University, Private Bag 11-222, Palmerston North, New Zealand
| |
Collapse
|
3
|
Umair S, Bouchet CLG, Deng Q, Palevich N, Simpson HV. Characterisation of a Teladorsagia circumcincta glutathione transferase. Mol Biochem Parasitol 2020; 239:111316. [PMID: 32889102 DOI: 10.1016/j.molbiopara.2020.111316] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 12/20/2022]
Abstract
A 615 bp full length cDNA encoding a Teladorsagia circumcincta glutathione transferase (TcGST) was cloned, expressed in Escherichia coli and the recombinant protein purified and its kinetic properties determined. The predicted protein consisted of 205 amino acids and was present as a single band of about 24 kDa on SDS-PAGE. Multiple alignments of the protein sequence of TcGST with homologues from other helminths showed that the highest identity of 53-68% with haem-binding nematode proteins designated as members of the nu class of GSTs. Substrate binding sites and conserved regions were identified and were generally conserved. The predicted 3-dimensional structures of TcGST and HcGST revealed highly open binding cavities typical of this class of GST, considered to allow greater accessibility to diverse ligands compared with other classes of GST. At 25 °C, the optimum pH for TcGST activity was pH 7, the Vmax was 1535 ± 33 nmoles.min-1. mg-1 protein and the apparent Km for the substrate 1-chloro-2,4-dinitrobenzene (CDNB) was 0.22 ± 0.01 mM (mean ± SD, n = 2). Antibodies in both serum and saliva from field-immune, but not nematode-naïve, sheep, recognised recombinant TcGST in enzyme-linked immunosorbent assays. The recognition of the recombinant protein by antibodies generated by exposure of sheep to the native enzyme indicates similar antigenicity of the two proteins. These findings could aid in the design of novel drugs and vaccine antigens for economically important parasites of livestock.
Collapse
Affiliation(s)
- Saleh Umair
- AgResearch Ltd, Private Bag 11-008, Palmerston North, New Zealand.
| | | | - Qing Deng
- AgResearch Ltd, Private Bag 11-008, Palmerston North, New Zealand
| | - Nikola Palevich
- AgResearch Ltd, Private Bag 11-008, Palmerston North, New Zealand
| | - Heather V Simpson
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand
| |
Collapse
|
4
|
Umair S, Bouchet CLG, Knight JS, Pernthaner A, Simpson HV. Molecular and biochemical characterisation and recognition by the immune host of the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) of the abomasal nematode parasite Teladorsagia circumcincta. Exp Parasitol 2017; 181:40-46. [PMID: 28757123 DOI: 10.1016/j.exppara.2017.07.006] [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] [Received: 02/22/2017] [Revised: 07/18/2017] [Accepted: 07/26/2017] [Indexed: 10/19/2022]
Abstract
A 1023 bp full length cDNA encoding Teladorsagia circumcincta GAPDH (TeciGAPDH) was cloned, expressed in Escherichia coli and the recombinant protein purified and its kinetic properties determined. A phylogenetic tree was constructed using helminth GAPDH sequences. The predicted protein consisted of 341 amino acids and was present as a single band of about 38 kDa on SDS-PAGE. Multiple alignments of the protein sequence of TeciGAPDH with homologues from other helminths showed that the greatest similarity (93%) to the GAPDH of Haemonchus contortus and Dictyocaulus viviparus, 82-86% similarity to the other nematode sequences and 68-71% similarity to cestode and trematode enzymes. Substrate binding sites and conserved regions were identified and were completely conserved in other homologues. At 25 °C, the optimum pH for TeciGAPDH activity was pH 8, the Vmax was 1052 ± 23 nmol min-1 mg-1 protein and the apparent Km for the substrate glyceraldehyde-3-phosphate was 0.02 ± 0.01 mM (both mean ± SD, n = 2). Antibodies in both serum and saliva from field-immune, but not nematode-naïve, sheep recognised recombinant TeciGAPDH in enzyme-linked immunosorbent assays. The recognition of the recombinant protein by antibodies generated by exposure of sheep to native GAPDH indicates similar antigenicity of the two proteins.
Collapse
Affiliation(s)
- S Umair
- AgResearch Ltd, Private Bag 11-008, Palmerston North, New Zealand.
| | - C L G Bouchet
- AgResearch Ltd, Private Bag 11-008, Palmerston North, New Zealand
| | - J S Knight
- AgResearch Ltd, Private Bag 11-008, Palmerston North, New Zealand
| | - A Pernthaner
- AgResearch Ltd, Private Bag 11-008, Palmerston North, New Zealand
| | - H V Simpson
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand
| |
Collapse
|
5
|
Umair S, Bouchet CLG, Knight JS, Pernthaner A, Simpson HV. Molecular and biochemical characterisation and recognition by the immune host of the enolase of the abomasal nematode parasite Teladorsagia circumcincta. Exp Parasitol 2016; 172:30-38. [PMID: 27939767 DOI: 10.1016/j.exppara.2016.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 11/28/2016] [Accepted: 12/05/2016] [Indexed: 10/20/2022]
Abstract
A 1299 bp full length cDNA encoding Teladorsagia circumcincta enolase (TeciENO) was cloned, expressed in Escherichia coli and the recombinant protein purified and its kinetic properties determined. Helminth enolase sequences were used to construct a phylogenetic tree. The predicted protein consisted of 433 amino acids and was present as a single band of about 50 kDa on SDS-PAGE. Multiple alignments of the protein sequence of TeciENO with homologues from other helminths showed 98% similarity with Haemonchus contortus enolase, 78-95% similarity to other nematode sequences and 72-75% similarity to cestode and trematode enolases. Substrate binding sites and conserved regions were identified and were completely conserved in other homologues. The optimum pH for TeciENO activity at 25 °C was pH 7, the Km for 2-phophoglycerate 0.09 ± 0.04 mM and the Vmax was 604 ± 6 nmol min-1 mg-1 protein (both mean ± SD, n = 2). TeciENO activity was inhibited by 11.5% by 1 mM citrate (p < 0.001). Antibodies in both serum and saliva from field-immune, but not nematode-naïve, sheep recognised recombinant TeciENO in enzyme-linked immunosorbent assays. The recognition of the recombinant protein by antibodies generated by exposure of sheep to native enolase indicates similar antigenicity of the two proteins.
Collapse
Affiliation(s)
- S Umair
- AgResearch Ltd, Private Bag 11-008, Palmerston North, New Zealand.
| | - C L G Bouchet
- AgResearch Ltd, Private Bag 11-008, Palmerston North, New Zealand
| | - J S Knight
- AgResearch Ltd, Private Bag 11-008, Palmerston North, New Zealand
| | - A Pernthaner
- AgResearch Ltd, Private Bag 11-008, Palmerston North, New Zealand
| | - H V Simpson
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand
| |
Collapse
|
6
|
Molecular and biochemical characterisation of abomasal nematode parasites Teladorsagia circumcincta and Haemonchus contortus phosphofructokinases and their recognition by the immune host. Exp Parasitol 2015; 151-152:64-72. [PMID: 25662436 DOI: 10.1016/j.exppara.2015.01.020] [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] [Received: 10/16/2014] [Revised: 01/28/2015] [Accepted: 01/29/2015] [Indexed: 11/23/2022]
Abstract
Full length cDNAs encoding phosphofructokinase (PFK) were cloned from Teladorsagia circumcincta (TcPFK) and Haemonchus contortus (HcPFK). TcPFK (2361 bp) and HcPFK (2367 bp) cDNA encoded 787 and 789 amino acid proteins respectively. The predicted amino acid sequences showed 98% similarity with each other and 70% with a Caenorhabditis elegans PFK. Substrate binding sites were completely conserved in both proteins. Soluble N-terminal His-tagged PFK proteins were expressed in Escherichia coli strain BL21, purified and characterised. The recombinant TcPFK and HcPFK had very similar kinetic properties: the pH optima were pH 7.0, Km for fructose 6-phosphate was 0.50 ± 0.01 and 0.55 ± 0.01 mM respectively when higher (inhibiting concentration, 0.3 mM) ATP concentration was used and the curve was sigmoidal. The Vmax for TcPFK and HcPFK were 1110 ± 16 and 910 ± 10 nM min(-1 )mg(-1) protein respectively. Lower ATP concentration (non-inhibiting, 0.01 mM) did not change the Vmax for TcPFK and HcPFK (890 ± 10 and 860 ± 12 nM min(-1 )mg(-1) protein) but the substrate affinity doubled and Km for fructose 6-phosphate were 0.20 ± 0.05 and 0.25 ± 0.01 mM respectively. Recognition of TcPFK and HcPFK by mucosal and serum antibodies in nematode exposed animals demonstrates antigenicity and suggests involvement in the host response to nematode infection.
Collapse
|
7
|
Umair S, Knight JS, Bland RJ, Simpson HV. Molecular and biochemical characterisation of arginine kinases in Haemonchus contortus and Teladorsagia circumcincta. Exp Parasitol 2013; 134:362-7. [PMID: 23583781 DOI: 10.1016/j.exppara.2013.03.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 02/21/2013] [Accepted: 03/17/2013] [Indexed: 12/23/2022]
Abstract
Full length cDNA encoding arginine kinases (AK) were cloned from Teladorsagia circumcincta (TcAK) and Haemonchus contortus (HcAK). The TcAK and HcAK cDNA (1080 bp) encoded 360 amino acid proteins. The predicted amino acid sequence showed 99% similarity with each other and 94% with a Caenorhabditis elegans AK. Soluble N-terminal His-tagged AK proteins were expressed in Escherichia coli strain BL21, purified and characterised. All binding sites were completely conserved in both proteins. The recombinant TcAK and HcAK had very similar kinetic properties: K(m) arginine was 0.35 mM, K(m) ATP was 0.8-0.9 mM and the pH optima were pH 7.5. Arginine analogues strongly inhibited recombinant enzyme activities (up to 80%), whilst other amino acids decreased activities by a maximum of 20%. TcAK and HcAK are potential vaccine candidates because of the strong antigenicity of invertebrate phosphagens and kinases and presence in metabolically active parts of the worm.
Collapse
Affiliation(s)
- S Umair
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11-222, Palmerston North, New Zealand.
| | | | | | | |
Collapse
|