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Hohenwarter L, Böttger R, Li SD. Modification and Delivery of Enkephalins for Pain Modulation. Int J Pharm 2023; 646:123425. [PMID: 37739096 DOI: 10.1016/j.ijpharm.2023.123425] [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: 04/06/2023] [Revised: 08/23/2023] [Accepted: 09/15/2023] [Indexed: 09/24/2023]
Abstract
Chronic pain negatively affects patient's quality of life and poses a significant economic burden. First line pharmaceutical treatment of chronic pain, including NSAIDs or antidepressants, is often inefficient to reduce pain, or produces intolerable adverse effects. In such cases, opioids are frequently prescribed for their potent analgesia, but chronic opioid use is also frequently associated with debilitating side effects that may offset analgesic benefits. Nonetheless, opioids continue to be widely utilized due to the lack of effective alternative analgesics. Since their discovery in 1975, a class of endogenous opioids called enkephalins (ENKs) have been investigated for their ability to relieve pain with significantly reduced adverse effects compared to conventional opioids. Their low metabolic stability and inability to cross biological membranes, however, make ENKs ineffective analgesics. Over past decades, much effort has been invested to overcome these limitations and develop ENK-based pain therapies. This review summarizes and describes chemical modifications and ENK delivery technologies utilizing ENK conjugates, nanoparticles and ENK gene delivery approaches and discusses valid lessons, challenges, and future directions of this evolving field.
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Affiliation(s)
- Lukas Hohenwarter
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Roland Böttger
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Shyh-Dar Li
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.
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2
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An Effective and Safe Enkephalin Analog for Antinociception. Pharmaceutics 2021; 13:pharmaceutics13070927. [PMID: 34206631 PMCID: PMC8308721 DOI: 10.3390/pharmaceutics13070927] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/14/2021] [Accepted: 06/18/2021] [Indexed: 11/17/2022] Open
Abstract
Opioids account for 69,000 overdose deaths per annum worldwide and cause serious side effects. Safer analgesics are urgently needed. The endogenous opioid peptide Leu-Enkephalin (Leu-ENK) is ineffective when introduced peripherally due to poor stability and limited membrane permeability. We developed a focused library of Leu-ENK analogs containing small hydrophobic modifications. N-pivaloyl analog KK-103 showed the highest binding affinity to the delta opioid receptor (68% relative to Leu-ENK) and an extended plasma half-life of 37 h. In the murine hot-plate model, subcutaneous KK-103 showed 10-fold improved anticonception (142%MPE·h) compared to Leu-ENK (14%MPE·h). In the formalin model, KK-103 reduced the licking and biting time to ~50% relative to the vehicle group. KK-103 was shown to act through the opioid receptors in the central nervous system. In contrast to morphine, KK-103 was longer-lasting and did not induce breathing depression, physical dependence, and tolerance, showing potential as a safe and effective analgesic.
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3
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Gein SV, Baeva TA. [Endomorphins: structure, localization, immunoregulatory activity]. ACTA ACUST UNITED AC 2020; 66:78-86. [PMID: 33351316 DOI: 10.14341/probl10364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 12/09/2019] [Accepted: 01/25/2020] [Indexed: 11/06/2022]
Abstract
Endomorphins – endogenous tetrapeptides with the highest affinity for the µ-opioid receptor. Currently, two tetrapeptides that differ in one amino acid residue have been isolated and characterized. The structure of endomorphins differs from the structure of members of three main families of opioid peptides: endorphins, enkephalins, and dynorphins, which contain the same N-terminal sequence. In the central nervous system, endomorphins are distributed everywhere, where they are primarily responsible for antinociception. Distribution of endomorphins in the immune system, similar to that of other opioid peptides, has allowed to suggest their active participation in the processes of immune regulation. This review summarizes modern views on the structure of endomorphins, their localization, possible intracellular mechanisms of signal transmission and their effects on the processes of activation, proliferation and differentiation of cells of innate and adaptive immunity. Endomorphins actively modulate the functions of the cells of the immune system. Peptides predominantly suppress adaptive immunity reactions. There effects on the functions of innate immunity cells (granulocytes, macrophages, monocytes, dendritic cells) depending on the conditions and can have either an inhibitory or stimulating orientation. Thus, endomorphins can be promising compounds that can effectively regulate both nociceptive signals and processes in the immune system.
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Affiliation(s)
- Sergey V Gein
- Institute of ecology and genetics of microorganisms - branch of the Perm Federal Research Center of the Ural Branch of the Russian Academy of Sciences; Perm State University
| | - Tatyana A Baeva
- Institute of ecology and genetics of microorganisms - branch of the Perm Federal Research Center of the Ural Branch of the Russian Academy of Sciences
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Dolberg AM, Reichl S. Expression analysis of human solute carrier (SLC) family transporters in nasal mucosa and RPMI 2650 cells. Eur J Pharm Sci 2018; 123:277-294. [PMID: 30041030 DOI: 10.1016/j.ejps.2018.07.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 06/24/2018] [Accepted: 07/18/2018] [Indexed: 12/13/2022]
Abstract
With nearly 400 members, the solute-linked carrier (SLC) superfamily is one of the most important gene classes concerning the disposition of drugs and the transport of physiological substrates in the human body. The mapping of related transport proteins is already well advanced for the intestines, kidneys and liver, but it has recently been brought into focus for various respiratory epithelia. The aim of this study was to evaluate the expression of several SLC transporters in differently cultured RPMI 2650 cells, as well as in specimens of the human nasal mucosa. The expression profiles of PEPT2, OATP1A2, OATP4C1, OCT2, OCTN1 and OCTN2 were investigated at the gene and protein levels by performing RT-PCR, western blot analysis and immunohistological staining. Uptake assays using appropriate substrates and inhibitory substances were performed to compare the activity of peptide, organic anion and organic cation transporters, respectively, among the three models. Expression of the six SLC transporters under investigation was confirmed at the mRNA and protein levels in human nasal mucosa ex vivo as well as in RPMI 2650 cells grown under different culture conditions. The functionality was almost equal among all of the models for the PEPT and OCT(N) transporters, while the functional activity of the OATP transporters was more pronounced for both in vitro models than for excised nasal tissue. Despite negligible variations in transporter capacities, the RPMI 2650 cell cultures and freshly isolated human nasal epithelium showed nearly comparable expression patterns for the examined SLC proteins. Therefore, in vitro models based on the RPMI 2650 cell line could provide helpful data during the preclinical investigation of intranasally administered drug formulations and in the development of strategies to target nasal drug transporters for either local or systemic drug delivery.
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Affiliation(s)
- Anne M Dolberg
- Institut für Pharmazeutische Technologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Stephan Reichl
- Institut für Pharmazeutische Technologie, Technische Universität Braunschweig, Braunschweig, Germany; Zentrum für Pharmaverfahrenstechnik, Technische Universität Braunschweig, Braunschweig, Germany.
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Zupančič O, Rohrer J, Thanh Lam H, Grießinger JA, Bernkop-Schnürch A. Development and in vitro characterization of self-emulsifying drug delivery system (SEDDS) for oral opioid peptide delivery. Drug Dev Ind Pharm 2017; 43:1694-1702. [DOI: 10.1080/03639045.2017.1338722] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Ožbej Zupančič
- Department of Pharmaceutical Technology, Institute of Pharmacy, Leopold-Franzens-University Innsbruck, Innsbruck, Austria
| | - Julia Rohrer
- Department of Pharmaceutical Technology, Institute of Pharmacy, Leopold-Franzens-University Innsbruck, Innsbruck, Austria
| | - Hung Thanh Lam
- Department of Pharmaceutical Technology, Institute of Pharmacy, Leopold-Franzens-University Innsbruck, Innsbruck, Austria
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Can Tho University of Medicine and Pharmacy, Can Tho City, Vietnam
| | - Julia Anita Grießinger
- Department of Pharmaceutical Technology, Institute of Pharmacy, Leopold-Franzens-University Innsbruck, Innsbruck, Austria
| | - Andreas Bernkop-Schnürch
- Department of Pharmaceutical Technology, Institute of Pharmacy, Leopold-Franzens-University Innsbruck, Innsbruck, Austria
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Eskandari S, Stephenson RJ, Fuaad AA, Apte SH, Doolan DL, Toth I. Synthesis and Characterisation of Self-Assembled and Self-Adjuvanting Asymmetric Multi-Epitope Lipopeptides of Ovalbumin. Chemistry 2014; 21:1251-61. [DOI: 10.1002/chem.201404997] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Indexed: 01/25/2023]
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Kumar A, Pandey AN, Jain SK. Nasal-nanotechnology: revolution for efficient therapeutics delivery. Drug Deliv 2014; 23:681-93. [PMID: 24901207 DOI: 10.3109/10717544.2014.920431] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
CONTEXT In recent years, nanotechnology-based delivery systems have gained interest to overcome the problems of restricted absorption of therapeutic agents from the nasal cavity, depending upon the physicochemical properties of the drug and physiological properties of the human nose. OBJECTIVE The well-tolerated and non-invasive nasal drug delivery when combined with the nanotechnology-based novel formulations and carriers, opens the way for the effective systemic and brain targeting delivery of various therapeutic agents. To accomplish competent drug delivery, it is imperative to recognize the interactions among the nanomaterials and the nasal biological environment, targeting cell-surface receptors, drug release, multiple drug administration, stability of therapeutic agents and molecular mechanisms of cell signaling involved in patho-biology of the disease under consideration. METHODS Quite a few systems have been successfully formulated using nanomaterials for intranasal (IN) delivery. Carbon nanotubes (CNTs), chitosan, polylactic-co-glycolic acid (PLGA) and PLGA-based nanosystems have also been studied in vitro and in vivo for the delivery of several therapeutic agents which shown promising concentrations in the brain after nasal administration. RESULTS AND CONCLUSION The use of nanomaterials including peptide-based nanotubes and nanogels (NGs) for vaccine delivery via nasal route is a new approach to control the disease progression. In this review, the recent developments in nanotechnology utilized for nasal drug delivery have been discussed.
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Affiliation(s)
- Amrish Kumar
- a Department of Pharmaceutics , Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University) , Bilaspur , Chhattisgarh , India
| | - Aditya Nath Pandey
- a Department of Pharmaceutics , Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University) , Bilaspur , Chhattisgarh , India
| | - Sunil Kumar Jain
- a Department of Pharmaceutics , Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University) , Bilaspur , Chhattisgarh , India
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Christie MP, Simerská P, Jen FEC, Hussein WM, Rawi MFM, Hartley-Tassell LE, Day CJ, Jennings MP, Toth I. A drug delivery strategy: binding enkephalin to asialoglycoprotein receptor by enzymatic galactosylation. PLoS One 2014; 9:e95024. [PMID: 24736570 PMCID: PMC3988166 DOI: 10.1371/journal.pone.0095024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 03/21/2014] [Indexed: 11/23/2022] Open
Abstract
Glycosylation of biopharmaceuticals can mediate cell specific delivery by targeting carbohydrate receptors. Additionally, glycosylation can improve the physico-chemical (drug-like) properties of peptide based drug candidates. The main purpose of this study was to examine if glycosylation of the peptide enkephalin could facilitate its binding to the carbohydrate receptor, asialoglycoprotein. Firstly, we described the one-pot enzymatic galactosylation of lactose modified enkephalin in the presence of uridine-5'-diphosphogalactose 4-epimerase and lipopolysaccharyl α-1,4-galactosyltransferase. Stability experiments using human plasma and Caco-2 cell homogenates showed that glycosylation considerably improved the stability of enkephalin (at least 60% remained stable after a 2 hr incubation at 37°C). In vitro permeability experiments using Caco-2 cells revealed that the permeability of mono- and trisaccharide conjugated enkephalins was 14 and 28 times higher, respectively, than that of enkephalin alone (Papp 3.1×10-8 cm/s). By the methods of surface plasmon resonance and molecular modeling, we demonstrated that the enzymatic glycosylation of enkephalin enabled binding the asialoglycoprotein receptor. The addition of a trisaccharide moiety to enkephalin improved the binding of enkephalin to the asialoglycoprotein receptor two fold (KD = 91 µM). The docking scores from molecular modeling showed that the binding modes and affinities of the glycosylated enkephalin derivatives to the asialoglycoprotein receptor complemented the results from the surface plasmon resonance experiments.
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Affiliation(s)
- Michelle P. Christie
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Pavla Simerská
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Freda E.-C. Jen
- Institute for Glycomics, Griffith University, Southport, Queensland, Australia
| | - Waleed M. Hussein
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Mohamad F. M. Rawi
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | | | - Christopher J. Day
- Institute for Glycomics, Griffith University, Southport, Queensland, Australia
| | - Michael P. Jennings
- Institute for Glycomics, Griffith University, Southport, Queensland, Australia
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
- School of Pharmacy, The University of Queensland, Pharmacy Australia Centre of Excellence, Woolloongabba, Queensland, Australia
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Cros CD, Toth I, Blanchfield JT. Delivery of a lactose derivative of endomorphin 1 to the brain via the olfactory epithelial pathway. Bioorg Med Chem Lett 2014; 24:1373-5. [DOI: 10.1016/j.bmcl.2014.01.041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 01/13/2014] [Accepted: 01/14/2014] [Indexed: 10/25/2022]
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10
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Varamini P, Toth I. Lipid- and sugar-modified endomorphins: novel targets for the treatment of neuropathic pain. Front Pharmacol 2013; 4:155. [PMID: 24379782 PMCID: PMC3862115 DOI: 10.3389/fphar.2013.00155] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 11/27/2013] [Indexed: 12/29/2022] Open
Abstract
Endomorphins are endogenous opioid peptides that cause potent antinociception in rodent models of acute and neuropathic pain with less undesirable side effects than opioid alkaloids. However, endomorphins are poorly suited to clinical applications because of low membrane permeability and a susceptibility to enzymatic degradation. Glycosylation and lipidation have proven to be two of the most robust approaches for the generation of new therapeutic endomorphin derivatives. Conjugation with lipoamino acids (LAA) confers an amphipathic character to the peptide, which improved interaction between the peptide and the lipid bilayer of the cell membranes, increasing permeability. Glycosylation can also improve peptide stability and blood brain barrier (BBB) transport. It is believed that an endocytotic mechanism (transcytosis) is responsible for the systemic delivery of water-soluble glycopeptides. This review discusses the application of glycosylation and lipidation strategies to improve the drug-like properties of endomorphins. Pharmacologically active endomorphin analogs with less adverse effects are also discussed.
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Affiliation(s)
- Pegah Varamini
- Medicinal Chemistry Department, School of Chemistry and Molecular Biosciences, The University of Queensland Brisbane, QLD, Australia
| | - Istvan Toth
- Medicinal Chemistry Department, School of Chemistry and Molecular Biosciences, The University of Queensland Brisbane, QLD, Australia ; Medicinal Chemistry Department, School of Pharmacy, The University of Queensland Brisbane, QLD, Australia
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11
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Simerska P, Christie MP, Goodwin D, Jen FEC, Jennings MP, Toth I. α-1,4-Galactosyltransferase-catalyzed glycosylation of sugar and lipid modified Leu-enkephalins. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcatb.2013.08.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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12
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Christie MP, Simerska P, Jen FEC, Jennings MP, Toth I. Liposomes for Improved Enzymatic Glycosylation of Lipid-Modified Lactose Enkephalin. Chempluschem 2013; 78:793-796. [PMID: 31986686 DOI: 10.1002/cplu.201300115] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 06/04/2013] [Indexed: 01/17/2023]
Abstract
Liposomes and enzymes: Liposome formulations improved solubility of a lipid-modified lactose enkephalin and, when used in enzymatic transformation, led to a twofold increase in glycosylation in comparison to substrate solubilised in 5 % dimethyl sulfoxide (DMSO; see figure).
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Affiliation(s)
- Michelle P Christie
- School of Chemistry and Molecular Biosciences, The University of Queensland, Cooper Road, St Lucia, QLD 4072 (Australia), Fax: (+61) 7-33654273
| | - Pavla Simerska
- School of Chemistry and Molecular Biosciences, The University of Queensland, Cooper Road, St Lucia, QLD 4072 (Australia), Fax: (+61) 7-33654273
| | - Freda E-C Jen
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, QLD 4125 (Australia)
| | - Michael P Jennings
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, QLD 4125 (Australia)
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences, The University of Queensland, Cooper Road, St Lucia, QLD 4072 (Australia), Fax: (+61) 7-33654273.,School of Pharmacy, The University of Queensland, Pharmacy Australia Centre of Excellence, Cornwall Street, Woolloongabba, QLD 4102 (Australia)
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13
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Wang ZJ, Spiccia ND, Jackson WR, Robinson AJ. Tandem Ru-alkylidene-catalysed cross metathesis/hydrogenation: synthesis of lipophilic amino acids. J Pept Sci 2013; 19:470-6. [DOI: 10.1002/psc.2522] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 04/20/2013] [Accepted: 04/22/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Zhen J Wang
- School of Chemistry, Monash University, Wellington Road, Melbourne, 3800, Victoria, Australia
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Varamini P, Hussein WM, Mansfeld FM, Toth I. Synthesis, biological activity and structure–activity relationship of endomorphin-1/substance P derivatives. Bioorg Med Chem 2012; 20:6335-43. [DOI: 10.1016/j.bmc.2012.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 08/24/2012] [Accepted: 09/01/2012] [Indexed: 10/27/2022]
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Proctor A, Wang Q, Lawrence DS, Allbritton NL. Development of a peptidase-resistant substrate for single-cell measurement of protein kinase B activation. Anal Chem 2012; 84:7195-202. [PMID: 22881604 PMCID: PMC3428732 DOI: 10.1021/ac301489d] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
An iterative design strategy using three criteria was utilized to develop a peptidase-resistant substrate peptide for protein kinase B. Libraries of peptides possessing non-native amino acids were screened for time to 50% phosphorylation, degradation half-life within a lysate, and appearance of a dominant fragment. The lead peptide possessed a half-life of 92 ± 7 and 16 ± 2 min in HeLa and LNCaP cytosolic lysates, respectively, representing a 4.6- and 2.7-fold lifetime improvement over that of the starting peptide. The redesigned peptide possessed a 4.5-fold improvement in phosphorylation efficiency compared to the starting peptide. The same peptide fragments were formed when the lead peptide was incubated in a lysate or loaded into single cells although the fragments formed in significantly different ratios suggesting that distinct peptidases metabolized the peptide in the two preparations. The rate of peptide degradation and phosphorylation was on average 0.1 ± 0.2 zmol pg(-1) s(-1) and 0.04 ± 0.08 zmol pg(-1) s(-1), respectively, for single LNCaP cells loaded with 4 ± 8 μM of peptide. Peptidase-resistant kinase substrates should find widespread utility in both lysate-based and single-cell assays of kinase activity.
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Affiliation(s)
- Angela Proctor
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Qunzhao Wang
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, USA
| | - David S. Lawrence
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, USA
- Division of Chemical Biology and Medicinal Chemistry, School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Nancy L. Allbritton
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC 27599, USA and North Carolina State University, Raleigh, NC 27695, USA
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Proctor A, Wang Q, Lawrence DS, Allbritton NL. Metabolism of peptide reporters in cell lysates and single cells. Analyst 2012; 137:3028-38. [PMID: 22314840 PMCID: PMC3697743 DOI: 10.1039/c2an16162a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The stability of an Abl kinase substrate peptide in a cytosolic lysate and in single cells was characterized. In the cytosolic lysate, the starting peptide was metabolized at an average initial rate of 1.7 ± 0.3 zmol pg(-1) s(-1) with a t(1/2) of 1.3 min. Five different fragments formed over time; however, a dominant cleavage site was identified. Multiple rational design cycles were utilized to develop a lead peptide with a phenylalanine and alanine replaced by an (N-methyl)phenylalanine and isoleucine, respectively, to attain cytosolic peptidase resistance while maintaining Abl substrate efficacy. This lead peptide possessed a 15-fold greater lifetime in the cytosolic lysate while attaining a 7-fold improvement in k(cat) as an Abl kinase substrate compared to the starting peptide. However, when loaded into single cells, the starting peptide and lead peptide possessed nearly identical degradation rates and an altered pattern of fragmentation relative to that in cell lysates. Preferential accumulation of a fragment with cleavage at an Ala-Ala bond in single cells suggested that dissimilar peptidases act on the peptides in the lysate versus single cells. A design strategy for peptide stabilization, analogous to that demonstrated for the lysate, should be effective for stabilization in single cells.
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Affiliation(s)
- Angela Proctor
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, USA
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