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Hao F, Feng Y, Guan Y. Light Chain LC and TAT-EGFP-HCS of Botulinum Toxin Expression and Biological Function in vitro and in vivo. CURR PROTEOMICS 2019. [DOI: 10.2174/1570164615666180817100248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Objective: To verify whether the botulinum toxin heavy chain HCS has specific neuronal
targeting function and to confirm whether TAT-EGFP-LC has hydrolyzable SNAP-25 and has transmembrane
biological activity.
Methods:
We constructed the pET-28a-TAT-EGFP-HCS/LC plasmid. After the plasmid is expressed
and purified, we co-cultured it with nerve cells or tumors. In addition, we used Western-Blot to identify
whether protein LC and TAT-EGFP-LC can digest the protein SNAP-25.
Results:
Fluorescence imaging showed that PC12, BV2, C6 and HeLa cells all showed green fluorescence,
and TAT-EGFP-HCS had the strongest fluorescence. Moreover, TAT-EGFP-LC can hydrolyze
intracellular SNAP-25 in PC12 cells, C6 cells, BV2 cells and HeLa, whereas LC alone cannot. In addition,
the in vivo protein TAT-EGFP-HCS can penetrate the blood-brain barrier and enter mouse brain
tissue.
Conclusion:
TAT-EGFP-HSC expressed in vitro has neural guidance function and can carry large proteins
across the cell membrane without influencing the biological activity.
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Affiliation(s)
- Fengjin Hao
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, Liaoning, 110122, China
| | - Yueqin Feng
- Department of Ultrasound, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, 110001, China
| | - Yifu Guan
- Department of Biochemistry and Molecular Biology, China Medical University, Shenyang, Liaoning, 110122, China
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Saffarian P, Peerayeh SN, Amani J, Ebrahimi F, Sedighianrad H, Halabian R, Imani Fooladi AA. Expression and purification of recombinant TAT-BoNT/A (1-448) under denaturing and native conditions. Bioengineered 2016; 7:478-483. [PMID: 27566060 PMCID: PMC5241812 DOI: 10.1080/21655979.2016.1201252] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 06/08/2016] [Accepted: 06/08/2016] [Indexed: 10/21/2022] Open
Abstract
Botulinum toxin type A can temporarily inhibit muscle contraction. Currently, physicians administer this toxin as a bio-drug in treatment of some muscle contraction disorders. TAT-BoNT/A(1-448) is a functional recombinant protein derived from botulinum toxin light chain. Unlike the full length botulinum toxin, TAT-BoNT/A(1-448) is a self-permeable molecule which can pass through bio-surfaces so can be used as a topical therapeutic agent without injection. To maintain the functionality of TAT-BoNT/A(1-448), it is necessary to restore its normal folding upon expression and purification. In this study, we have investigated and optimized expression conditions for this novel recombinant protein. Under denaturing condition (1 mM IPTG, at 37°C), the chimeric protein was produced as inclusion body and required to be purified using denaturing agents (e.g. urea). Yet, lower incubation temperature (18°C) and less IPTG concentration (0.5 mM) induce a protein under native condition. In such condition, about 60% of the chimeric protein was expressed in soluble form.
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Affiliation(s)
- Parvaneh Saffarian
- Department of Microbiology, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran
| | - Shahin Najar Peerayeh
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Jafar Amani
- Department of Biology, Faculty of Basic Sciences, Imam Hussein University, Tehran, Iran
| | - Firooz Ebrahimi
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Hamid Sedighianrad
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Raheleh Halabian
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Abbas Ali Imani Fooladi
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
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3
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Saffarian P, Peerayeh SN, Amani J, Ebrahimi F, Sedighian H, Halabian R, Fooladi AAI. TAT-BoNT/A(₁₋₄₄₈), a novel fusion protein as a therapeutic agent: analysis of transcutaneous delivery and enzyme activity. Appl Microbiol Biotechnol 2015; 100:2785-95. [PMID: 26711279 DOI: 10.1007/s00253-015-7240-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 12/02/2015] [Accepted: 12/05/2015] [Indexed: 12/11/2022]
Abstract
Botulinum neurotoxin type A (BoNT/A) has been used as an injectable therapeutic agent for the treatment of some abnormal muscle contractions. In this study, TAT(47-57) peptide, a cell-penetrating peptide, was fused with the catalytic domain of BoNT/A for therapeutic purposes. HeLa and BE(2)-C cell lines were treated separately with purified TAT-BoNT/A(1-448) recombinant protein, and transduction of protein was analyzed by western blotting. Also, transcutaneous delivery through mouse skin surface was evaluated by immunohistochemistry. The in vitro catalytic activity of TAT-BoNT/A(1-448) was evaluated by HPLC. The presence of recombinant protein was detected in both of the cell lines as well as mouse skin cryosections after 60 and 120 min of incubation. The concentration of intracellular proteins was increased over time. HPLC analysis showed that this fusion protein has a biological activity 1.5 times as much as the full-length BoNT/A(1-448) protein. TAT-BoNT/A(1-448) fusion protein is biologically active and can transmit through living cells in vitro and in vivo successfully and more effectively compared with BoNT/A(1-448) protein as control.
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Affiliation(s)
- Parvaneh Saffarian
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Shahin Najar Peerayeh
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Jafar Amani
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Firooz Ebrahimi
- Department of Biology, Faculty of Basic Sciences, Imam Hussein University, Tehran, Iran
| | - Hamid Sedighian
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Raheleh Halabian
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Abbas Ali Imani Fooladi
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
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Wang D, Krilich J, Baudys J, Barr JR, Kalb SR. Enhanced detection of type C botulinum neurotoxin by the Endopep-MS assay through optimization of peptide substrates. Bioorg Med Chem 2015; 23:3667-73. [PMID: 25913863 DOI: 10.1016/j.bmc.2015.04.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/25/2015] [Accepted: 04/03/2015] [Indexed: 10/23/2022]
Abstract
It is essential to have a simple, quick and sensitive method for the detection and quantification of botulinum neurotoxins, the most toxic substances and the causative agents of botulism. Type C botulinum neurotoxin (BoNT/C) represents one of the seven members of distinctive BoNT serotypes (A to G) that cause botulism in animals and avians. Here we report the development of optimized peptide substrates for improving the detection of BoNT/C and /CD mosaic toxins using an Endopep-MS assay, a mass spectrometry-based method that is able to rapidly and sensitively detect and differentiate all types of BoNTs by extracting the toxin with specific antibodies and detecting the unique cleavage products of peptide substrates. Based on the sequence of a short SNAP-25 peptide, we conducted optimization through a comprehensive process including length determination, terminal modification, single and multiple amino acid residue substitution, and incorporation of unnatural amino acid residues. Our data demonstrate that an optimal peptide provides a more than 200-fold improvement over the substrate currently used in the Endopep-MS assay for the detection of BoNT/C1 and /CD mosaic. Using the new substrate in a four-hour cleavage reaction, the limit of detection for the BoNT/C1 complex spiked in buffer, serum and milk samples was determined to be 0.5, 0.5 and 1mouseLD50/mL, respectively, representing a similar or higher sensitivity than that obtained by traditional mouse bioassay.
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Affiliation(s)
- Dongxia Wang
- Division of Laboratory Sciences, National Center for the Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, Atlanta, GA 30341, United States
| | - Joan Krilich
- Division of Laboratory Sciences, National Center for the Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, Atlanta, GA 30341, United States
| | - Jakub Baudys
- Division of Laboratory Sciences, National Center for the Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, Atlanta, GA 30341, United States
| | - John R Barr
- Division of Laboratory Sciences, National Center for the Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, Atlanta, GA 30341, United States
| | - Suzanne R Kalb
- Division of Laboratory Sciences, National Center for the Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, Atlanta, GA 30341, United States.
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Montgomery VA, Ahmed SA, Olson MA, Mizanur RM, Stafford RG, Roxas-Duncan VI, Smith LA. Ex vivo inhibition of Clostridium botulinum neurotoxin types B, C, E, and F by small molecular weight inhibitors. Toxicon 2015; 98:12-9. [PMID: 25707753 DOI: 10.1016/j.toxicon.2015.02.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 02/06/2015] [Accepted: 02/19/2015] [Indexed: 11/28/2022]
Abstract
Two small molecular weight inhibitors, compounds CB7969312 and CB7967495, that displayed inhibition of botulinum neurotoxin serotype A in a previous study, were evaluated for inhibition of botulinum neurotoxin serotypes B, C, E, and F. The small molecular weight inhibitors were assessed by molecular modeling, UPLC-based peptide cleavage assay; and an ex vivo assay, the mouse phrenic nerve - hemidiaphragm assay (MPNHDA). While both compounds were inhibitors of botulinum neurotoxin (BoNT) serotypes B, C, and F in the MPNHDA, compound CB7969312 was effective at lower molar concentrations than compound CB7967495. However, compound CB7967495 was significantly more effective at preventing BoNTE intoxication than compound CB7969312. In the UPLC-based peptide cleavage assay, CB7969312 was also more effective against LcC. Both compounds inhibited BoNTE, but not BoNTF, LcE, or LcF in the UPLC-based peptide cleavage assay. Molecular modeling studies predicted that both compounds would be effective inhibitors of BoNTs B, C, E, and F. But CB7967495 was predicted to be a more effective inhibitor of the four serotypes (B, C, E, and F) than CB7969312. This is the first report of a small molecular weight compound that inhibits serotypes B, C, E, and F in the ex vivo assay.
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Affiliation(s)
- Vicki A Montgomery
- U.S. Army Medical Research Institute of Infectious Diseases, Division of Molecular and Translational Sciences, 1425 Porter St. Ft Detrick, Frederick, MD, USA.
| | - S Ashraf Ahmed
- U.S. Army Medical Research Institute of Infectious Diseases, Division of Molecular and Translational Sciences, 1425 Porter St. Ft Detrick, Frederick, MD, USA.
| | - Mark A Olson
- U.S. Army Medical Research Institute of Infectious Diseases, Division of Molecular and Translational Sciences, 1425 Porter St. Ft Detrick, Frederick, MD, USA.
| | - Rahman M Mizanur
- U.S. Army Medical Research Institute of Infectious Diseases, Biosurety Division, 1430 Veterans Dr, Ft Detrick, Frederick, MD, USA(1).
| | - Robert G Stafford
- U.S. Army Medical Research Institute of Infectious Diseases, Division of Molecular and Translational Sciences, 1425 Porter St. Ft Detrick, Frederick, MD, USA.
| | - Virginia I Roxas-Duncan
- U.S. Army Medical Research Institute of Infectious Diseases, Biosurety Division, 1430 Veterans Dr, Ft Detrick, Frederick, MD, USA(1).
| | - Leonard A Smith
- Medical Countermeasures Technology, U.S. Army Medical Research and Material Command, 1425 Porter St. Ft Detrick, Frederick, MD, USA.
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Mizanur RM, Frasca V, Swaminathan S, Bavari S, Webb R, Smith LA, Ahmed SA. The C terminus of the catalytic domain of type A botulinum neurotoxin may facilitate product release from the active site. J Biol Chem 2013; 288:24223-33. [PMID: 23779108 DOI: 10.1074/jbc.m113.451286] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Botulinum neurotoxins are the most toxic of all compounds. The toxicity is related to a poor zinc endopeptidase activity located in a 50-kDa domain known as light chain (Lc) of the toxin. The C-terminal tail of Lc is not visible in any of the currently available x-ray structures, and it has no known function but undergoes autocatalytic truncations during purification and storage. By synthesizing C-terminal peptides of various lengths, in this study, we have shown that these peptides competitively inhibit the normal catalytic activity of Lc of serotype A (LcA) and have defined the length of the mature LcA to consist of the first 444 residues. Two catalytically inactive mutants also inhibited LcA activity. Our results suggested that the C terminus of LcA might interact at or near its own active site. By using synthetic C-terminal peptides from LcB, LcC1, LcD, LcE, and LcF and their respective substrate peptides, we have shown that the inhibition of activity is specific only for LcA. Although a potent inhibitor with a Ki of 4.5 μm, the largest of our LcA C-terminal peptides stimulated LcA activity when added at near-stoichiometric concentration to three versions of LcA differing in their C-terminal lengths. The result suggested a product removal role of the LcA C terminus. This suggestion is supported by a weak but specific interaction determined by isothermal titration calorimetry between an LcA C-terminal peptide and N-terminal product from a peptide substrate of LcA. Our results also underscore the importance of using a mature LcA as an inhibitor screening target.
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Affiliation(s)
- Rahman M Mizanur
- Integrated Toxicology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland 21702, USA
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Toth S, Brueggmann EE, Oyler GA, Smith LA, Hines HB, Ahmed SA. Tyrosine phosphorylation of botulinum neurotoxin protease domains. Front Pharmacol 2012; 3:102. [PMID: 22675300 PMCID: PMC3366388 DOI: 10.3389/fphar.2012.00102] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 05/07/2012] [Indexed: 01/17/2023] Open
Abstract
Botulinum neurotoxins are most potent of all toxins. Their N-terminal light chain domain (Lc) translocates into peripheral cholinergic neurons to exert its endoproteolytic action leading to muscle paralysis. Therapeutic development against these toxins is a major challenge due to their in vitro and in vivo structural differences. Although three-dimensional structures and reaction mechanisms are very similar, the seven serotypes designated A through G vastly vary in their intracellular catalytic stability. To investigate if protein phosphorylation could account for this difference, we employed Src-catalyzed tyrosine phosphorylation of the Lc of six serotypes namely LcA, LcB, LcC1, LcD, LcE, and LcG. Very little phosphorylation was observed with LcD and LcE but LcA, LcB, and LcG were maximally phosphorylated by Src. Phosphorylation of LcA, LcB, and LcG did not affect their secondary and tertiary structures and thermostability significantly. Phosphorylation of Y250 and Y251 made LcA resistant to autocatalysis and drastically reduced its kcat/Km for catalysis. A tyrosine residue present near the essential cysteine at the C-terminal tail of LcA, LcB, and LcG was readily phosphorylated in vitro. Inclusion of a competitive inhibitor protected Y426 of LcA from phosphorylation, shedding light on the role of the C-terminus in the enzyme’s substrate or product binding.
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Affiliation(s)
- Stephen Toth
- Integrated Toxicology Division, Department of Biochemistry and Cell Biology, United States Army Medical Research Institute of Infectious Diseases Fort Detrick, MD, USA
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Rowe B, Schmidt JJ, Smith LA, Ahmed SA. Rapid product analysis and increased sensitivity for quantitative determinations of botulinum neurotoxin proteolytic activity. Anal Biochem 2010; 396:188-93. [DOI: 10.1016/j.ab.2009.09.034] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Revised: 09/18/2009] [Accepted: 09/20/2009] [Indexed: 10/20/2022]
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Substrate binding mode and its implication on drug design for botulinum neurotoxin A. PLoS Pathog 2008; 4:e1000165. [PMID: 18818739 PMCID: PMC2533696 DOI: 10.1371/journal.ppat.1000165] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Accepted: 08/28/2008] [Indexed: 11/19/2022] Open
Abstract
The seven antigenically distinct serotypes of Clostridium botulinum neurotoxins, the causative agents of botulism, block the neurotransmitter release by specifically cleaving one of the three SNARE proteins and induce flaccid paralysis. The Centers for Disease Control and Prevention (CDC) has declared them as Category A biowarfare agents. The most potent among them, botulinum neurotoxin type A (BoNT/A), cleaves its substrate synaptosome-associated protein of 25 kDa (SNAP-25). An efficient drug for botulism can be developed only with the knowledge of interactions between the substrate and enzyme at the active site. Here, we report the crystal structures of the catalytic domain of BoNT/A with its uncleavable SNAP-25 peptide (197)QRATKM(202) and its variant (197)RRATKM(202) to 1.5 A and 1.6 A, respectively. This is the first time the structure of an uncleavable substrate bound to an active botulinum neurotoxin is reported and it has helped in unequivocally defining S1 to S5' sites. These substrate peptides make interactions with the enzyme predominantly by the residues from 160, 200, 250 and 370 loops. Most notably, the amino nitrogen and carbonyl oxygen of P1 residue (Gln197) chelate the zinc ion and replace the nucleophilic water. The P1'-Arg198, occupies the S1' site formed by Arg363, Thr220, Asp370, Thr215, Ile161, Phe163 and Phe194. The S2' subsite is formed by Arg363, Asn368 and Asp370, while S3' subsite is formed by Tyr251, Leu256, Val258, Tyr366, Phe369 and Asn388. P4'-Lys201 makes hydrogen bond with Gln162. P5'-Met202 binds in the hydrophobic pocket formed by the residues from the 250 and 200 loop. Knowledge of interactions between the enzyme and substrate peptide from these complex structures should form the basis for design of potent inhibitors for this neurotoxin.
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