The pH Low Insertion Peptide (pHLIP) has versatile applications in several diseases due to its differential behavior at slightly different pH values. pHLIP is an unstructured and peripheral membrane-associated peptide at neutral pH and an α-helical transmembrane peptide at acidic values. Similar to what happened to insulin and growth hormone, pHLIP´s expanding applications require high-yield production to further scale-up its usefulness. To date, synthesis of the pHLIP has not been reported in a prokaryotic platform, mainly relying on solid-phase synthesis. Bacterial production arises as an option for high-amount peptide generation and larger pHLIP fusion protein-synthesis; however, cell-based pH-responsive peptide production could be challenging due to intracellular peptide interactions or degradation due to unstructured conformations. An Escherichia coli (E. coli)-BL21 cell culture was induced with Isopropyl ß-D-1-thiogalactopyranoside (IPTG) in order to produce a Glutathione S-transferase-pHLIP (GST-pHLIP) fusion construct. Purification was done with Glutathione (GSH)-decorated magnetic beads using 4 ml of the induced cell culture. The production was quantified with Bradford reagent and characterized with SDS-PAGE and Western blot, contrasting Bradford results with densitometry analysis to obtain production approximate absolute values. A purified approximate total yield of ~26 µg with an apparent GSH-bead saturation and a total production of ~82 µg was obtained. Our Western Blot assay confirmed the presence of the GST-pHLIP construct in all the IPTG-induced fractions. Conclusion: A high-yield pHLIP production irrespective of its membrane affinity in acidic environments or its unstructured nature was achieved. Our study could be useful to scale up pHLIP synthesis for future applications.
Citation: Oscar Cienfuegos-Jiménez, Abril Morales-Hernández, Olivia A. Robles-Rodríguez, Sergio Bustos-Montes, Kevin A. Bañuelos-Alduncin, Aurora R. Cortés-Castillo, Hugo D. Barreto-Hurtado, Luis Carrete-Salgado, Iván A. Marino-Martínez. High-yield production and purification of the fusion pH-responsive peptide GST-pHLIP in Escherichia coli BL21[J]. AIMS Molecular Science, 2022, 9(4): 136-144. doi: 10.3934/molsci.2022008
The pH Low Insertion Peptide (pHLIP) has versatile applications in several diseases due to its differential behavior at slightly different pH values. pHLIP is an unstructured and peripheral membrane-associated peptide at neutral pH and an α-helical transmembrane peptide at acidic values. Similar to what happened to insulin and growth hormone, pHLIP´s expanding applications require high-yield production to further scale-up its usefulness. To date, synthesis of the pHLIP has not been reported in a prokaryotic platform, mainly relying on solid-phase synthesis. Bacterial production arises as an option for high-amount peptide generation and larger pHLIP fusion protein-synthesis; however, cell-based pH-responsive peptide production could be challenging due to intracellular peptide interactions or degradation due to unstructured conformations. An Escherichia coli (E. coli)-BL21 cell culture was induced with Isopropyl ß-D-1-thiogalactopyranoside (IPTG) in order to produce a Glutathione S-transferase-pHLIP (GST-pHLIP) fusion construct. Purification was done with Glutathione (GSH)-decorated magnetic beads using 4 ml of the induced cell culture. The production was quantified with Bradford reagent and characterized with SDS-PAGE and Western blot, contrasting Bradford results with densitometry analysis to obtain production approximate absolute values. A purified approximate total yield of ~26 µg with an apparent GSH-bead saturation and a total production of ~82 µg was obtained. Our Western Blot assay confirmed the presence of the GST-pHLIP construct in all the IPTG-induced fractions. Conclusion: A high-yield pHLIP production irrespective of its membrane affinity in acidic environments or its unstructured nature was achieved. Our study could be useful to scale up pHLIP synthesis for future applications.
Isopropyl ß-D-1-thiogalactopyranoside
acidity-triggered rational membrane
pH Low Insertion Peptide
Glutathione S-transferase
Luria-Bertani broth
Glutathione
IPTG-induced purified protein
IPTG non-induced purified protein
IPTG-induced purification flow through
IPTG non-induced purification flow through
IPTG-induced crude lysate
Untransformed cell lysate
[1] | Erra Díaz F, Dantas E, Geffner J (2018) Unravelling the Interplay between Extracellular Acidosis and Immune Cells. Mediators Inflamm 2018: 1218297. https://doi.org/10.1155/2018/1218297 |
[2] | Nguyen VP, Alves DS, Scott HL, et al. (2015) A Novel Soluble Peptide with pH-Responsive Membrane Insertion. Biochemistry 54: 6567-6575. https://doi.org/10.1021/acs.biochem.5b00856 |
[3] | Weerakkody D, Moshnikova A, Thakur MS, et al. (2013) Family of pH (low) insertion peptides for tumor targeting. Proc Natl Acad Sci USA 110: 5834-5839. https://doi.org/10.1073/pnas.1303708110 |
[4] | Gupta C, Ren Y, Mertz B (2018) Cooperative Nonbonded Forces Control Membrane Binding of the pH-Low Insertion Peptide pHLIP. Biophys J 115: 2403-2412. https://doi.org/10.1016/j.bpj.2018.11.002 |
[5] | Scott HL, Westerfield JM, Barrera FN (2017) Determination of the Membrane Translocation pK of the pH-Low Insertion Peptide. Biophys J 113: 869-879. https://doi.org/10.1016/j.bpj.2017.06.065 |
[6] | Reshetnyak YK, Andreev OA, Segala M, et al. (2008) Energetics of peptide (pHLIP) binding to and folding across a lipid bilayer membrane. Proc Natl Acad Sci USA 105: 15340-15345. https://doi.org/10.1073/pnas.0804746105 |
[7] | Bauer D, Visca H, Weerakkody A, et al. (2022) PET Imaging of Acidic Tumor Environment With 89Zr-labeled pHLIP Probes. Front Oncol 12: 882541. https://doi.org/10.3389/fonc.2022.882541 |
[8] | Deskeuvre M, Lan J, Dierge E, et al. (2022) Targeting cancer cells in acidosis with conjugates between the carnitine palmitoyltransferase 1 inhibitor etomoxir and pH (low) insertion peptides. Int J Pharm 624: 122041. https://doi.org/10.1016/j.ijpharm.2022.122041 |
[9] | Andreev OA, Karabadzhak AG, Weerakkody D, et al. (2010) pH (low) insertion peptide (pHLIP) inserts across a lipid bilayer as a helix and exits by a different path. Proc Natl Acad Sci USA 107: 4081-4086. https://doi.org/10.1073/pnas.0914330107 |
[10] | Reshetnyak YK, Segala M, Andreev OA, et al. (2007) A monomeric membrane peptide that lives in three worlds: in solution, attached to, and inserted across lipid bilayers. Biophys J 93: 2363-2372. https://doi.org/10.1529/biophysj.107.109967 |
[11] | Slaybaugh G, Weerakkody D, Engelman DM, et al. (2020) Kinetics of pHLIP peptide insertion into and exit from a membrane. Proc Natl Acad Sci USA 117: 12095-12100. https://doi.org/10.1073/pnas.1917857117 |
[12] | Adochite RC, Moshnikova A, Carlin SD, et al. (2014) Targeting breast tumors with pH (low) insertion peptides. Mol Pharm 11: 2896-2905. https://doi.org/10.1021/mp5002526 |
[13] | Sosunov EA, Anyukhovsky EP, Sosunov AA, et al. (2013) pH (low) insertion peptide (pHLIP) targets ischemic myocardium. Proc Natl Acad Sci USA 110: 82-86. https://doi.org/10.1073/pnas.1220038110 |
[14] | Ding GB, Zhu C, Wang Q, et al. (2022) Molecularly engineered tumor acidity-responsive plant toxin gelonin for safe and efficient cancer therapy. Bioact Mater 18: 42-55. https://doi.org/10.1016/j.bioactmat.2022.02.001 |
[15] | Stráner P, Taricska N, Szabó M, et al. (2016) Bacterial expression and/or solid phase peptide synthesis of 20-40 amino acid long polypeptides and miniproteins, the case study of Class B GPCR ligands. Curr Protein Pept Sci 17: 147-155. https://doi.org/10.2174/1389203716666151102105215 |
[16] | Ji T, Lang J, Ning B, et al. (2019) Enhanced Natural Killer Cell Immunotherapy by Rationally Assembling Fc Fragments of Antibodies onto Tumor Membranes. Adv Mater 31: e1804395. https://doi.org/10.1002/adma.201804395 |
[17] | Trier NH, Hansen PR, Houen G (2012) Production and characterization of peptide antibodies. Methods 56: 136-144. https://doi.org/10.1016/j.ymeth.2011.12.001 |
[18] | Casey JR, Grinstein S, Orlowski J (2010) Sensors and regulators of intracellular pH. Nat Rev Mol Cell Biol 11: 50-61. https://doi.org/10.1038/nrm2820 |
[19] | Tsvetkov P, Myers N, Adler J, et al. (2020) Degradation of Intrinsically Disordered Proteins by the NADH 26S Proteasome. Biomolecules 10: 1642. https://doi.org/10.3390/biom10121642 |
[20] | Hunt JF, Rath P, Rothschild KJ, et al. (1997) Spontaneous, pH-dependent membrane insertion of a transbilayer alpha-helix. Biochemistry 36: 15177-15192. https://doi.org/10.1021/bi970147b |
[21] | Deacon JC, Engelman DM, Barrera FN (2015) Targeting acidity in diseased tissues: mechanism and applications of the membrane-inserting peptide, pHLIP. Arch Biochem Biophys 565: 40-48. https://doi.org/10.1016/j.abb.2014.11.002 |
[22] | Grimsley GR, Scholtz JM, Pace CN (2009) A summary of the measured pK values of the ionizable groups in folded proteins. Protein Sci 18: 247-251. https://doi.org/10.1002/pro.19 |
[23] | Spiess M, Junne T, Janoschke M (2019) Membrane Protein Integration and Topogenesis at the ER. Protein J 38: 306-316. https://doi.org/10.1007/s10930-019-09827-6 |
[24] | Paslawski W, Lillelund OK, Kristensen JV, et al. (2015) Cooperative folding of a polytopic α-helical membrane protein involves a compact N-terminal nucleus and nonnative loops. Proc Natl Acad Sci USA 112: 7978-7983. https://doi.org/10.1073/pnas.1424751112 |
[25] | Bañó-Polo M, Martínez-Gil L, Barrera FN, et al. (2019) Insertion of Bacteriorhodopsin Helix C Variants into Biological Membranes. ACS Omega 5: 556-560. https://doi.org/10.1021/acsomega.9b03126 |