1
|
Kurien BT, Scofield RH. Current Trends in Validating Antibody Specificities for ELISpot by Western Blotting. Methods Mol Biol 2024; 2768:15-27. [PMID: 38502385 DOI: 10.1007/978-1-0716-3690-9_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
The enzyme-linked immunospot (ELISpot) assay is a highly useful and sensitive method to detect total immunoglobulin and antigen-specific antibody-secreting cells. In addition, this method can measure biological activity and immunological secretions from immune cells. In general, membrane-bound antigen allows binding of antibody secreted by B cells, or a membrane-bound analyte-specific antibody binds to the specific analyte (e.g., cytokines) elicited from cells added to the well containing the bound antibody. The response from added cells is then detected by using an anti-Ig antibody and a colorimetric substrate, while in the case of non-B cells, the elicited antigen is detected with appropriate antibodies and enzyme-conjugated antibodies. Specificity of antibodies binding the protein of interest is necessary to achieve correct results. Western blotting can be used for this with/without siRNA knockdown of proteins of interest or with the use of peptide inhibitors to inhibit the binding of specific antibodies to the target protein. Despite its general simplicity, western blotting is a powerful technique for immunodetection of proteins (notably low abundance proteins) as it provides simultaneous resolution of multiple immunogenic antigens within a sample for detection by specific antibodies. Now, we have plethora of immunoblotting methods to validate antibodies for ELISpot.
Collapse
Affiliation(s)
- Biji T Kurien
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma, OK, USA.
- Department of Veterans Affairs Medical Center, Oklahoma City, Oklahoma, OK, USA.
| | - R Hal Scofield
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma, OK, USA
- Department of Veterans Affairs Medical Center, Oklahoma City, Oklahoma, OK, USA
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma, OK, USA
| |
Collapse
|
2
|
Subkhangulova A, Gonzalez-Lozano MA, Groffen AJA, van Weering JRT, Smit AB, Toonen RF, Verhage M. Tomosyn affects dense core vesicle composition but not exocytosis in mammalian neurons. eLife 2023; 12:e85561. [PMID: 37695731 PMCID: PMC10495110 DOI: 10.7554/elife.85561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 08/28/2023] [Indexed: 09/13/2023] Open
Abstract
Tomosyn is a large, non-canonical SNARE protein proposed to act as an inhibitor of SNARE complex formation in the exocytosis of secretory vesicles. In the brain, tomosyn inhibits the fusion of synaptic vesicles (SVs), whereas its role in the fusion of neuropeptide-containing dense core vesicles (DCVs) is unknown. Here, we addressed this question using a new mouse model with a conditional deletion of tomosyn (Stxbp5) and its paralogue tomosyn-2 (Stxbp5l). We monitored DCV exocytosis at single vesicle resolution in tomosyn-deficient primary neurons using a validated pHluorin-based assay. Surprisingly, loss of tomosyns did not affect the number of DCV fusion events but resulted in a strong reduction of intracellular levels of DCV cargos, such as neuropeptide Y (NPY) and brain-derived neurotrophic factor (BDNF). BDNF levels were largely restored by re-expression of tomosyn but not by inhibition of lysosomal proteolysis. Tomosyn's SNARE domain was dispensable for the rescue. The size of the trans-Golgi network and DCVs was decreased, and the speed of DCV cargo flux through Golgi was increased in tomosyn-deficient neurons, suggesting a role for tomosyns in DCV biogenesis. Additionally, tomosyn-deficient neurons showed impaired mRNA expression of some DCV cargos, which was not restored by re-expression of tomosyn and was also observed in Cre-expressing wild-type neurons not carrying loxP sites, suggesting a direct effect of Cre recombinase on neuronal transcription. Taken together, our findings argue against an inhibitory role of tomosyns in neuronal DCV exocytosis and suggests an evolutionary conserved function of tomosyns in the packaging of secretory cargo at the Golgi.
Collapse
Affiliation(s)
- Aygul Subkhangulova
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), Vrije Universiteit (VU) AmsterdamAmsterdamNetherlands
| | - Miguel A Gonzalez-Lozano
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research (CNCR), Vrije Universiteit (VU) AmsterdamAmsterdamNetherlands
| | - Alexander JA Groffen
- Department of Human Genetics, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam University Medical Center (UMC)AmsterdamNetherlands
| | - Jan RT van Weering
- Department of Human Genetics, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam University Medical Center (UMC)AmsterdamNetherlands
| | - August B Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research (CNCR), Vrije Universiteit (VU) AmsterdamAmsterdamNetherlands
| | - Ruud F Toonen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), Vrije Universiteit (VU) AmsterdamAmsterdamNetherlands
| | - Matthijs Verhage
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), Vrije Universiteit (VU) AmsterdamAmsterdamNetherlands
- Department of Human Genetics, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam University Medical Center (UMC)AmsterdamNetherlands
| |
Collapse
|
3
|
Liu D, Wu H, Cui S, Zhao Q. Comprehensive Optimization of Western Blotting. Gels 2023; 9:652. [PMID: 37623107 PMCID: PMC10453944 DOI: 10.3390/gels9080652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 08/11/2023] [Accepted: 08/11/2023] [Indexed: 08/26/2023] Open
Abstract
Western blotting is one of the most extensively used techniques in the biomedical field. However, it is criticized by many researchers due to its considerable time consumption, multiple steps, and low method results. Therefore, we modified the steps of gel preparation, electrophoresis, electrotransfer, blocking, and gel cutting. First, we simplified the gel preparation step by premixing various reagents and varying the amounts of catalysts or radical generators, which shortened the entire process to 10 min. Second, we shortened the electrophoresis process to 35 min by modifying the formula of the electrophoresis running buffer. Then, we removed the hazard of methanol vapor by replacing methanol with ethanol in the electrotransfer buffer. Finally, the use of polyvinylpyrrolidone-40 shortened the blocking procedure to 10 min. Our modifications shortened the time, improved the experimental productivity, and minimized the experimental cost without hindering compatibility with most existing equipment. The entire experiment up to primary antibody incubation can be completed within 80 min.
Collapse
Affiliation(s)
- Dishiwen Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China; (D.L.); (H.W.); (S.C.)
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, China
| | - Haoliang Wu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China; (D.L.); (H.W.); (S.C.)
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, China
| | - Shengyu Cui
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China; (D.L.); (H.W.); (S.C.)
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, China
| | - Qingyan Zhao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China; (D.L.); (H.W.); (S.C.)
- Cardiovascular Research Institute, Wuhan University, Wuhan 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, China
| |
Collapse
|
4
|
Kurien BT, Scofield RH. Validating Antibody Specificities for Immunohistochemistry by Protein Blotting. Methods Mol Biol 2022; 2593:21-33. [PMID: 36513922 DOI: 10.1007/978-1-0716-2811-9_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Optimized antibody reagents are important in research, and erratic antibody performance leads to variability in immunoassays. Specificity of antibodies binding the protein of interest is vital to obtain accurate results. Recommendations for validation and use of primary antibodies are unique to each type of immunoassay as the antibodies' performance is greatly affected by the assay context. Immunoblotting procedures have been used along with other important antibody-based detection methods like enzyme-linked immunosorbent assay and immunohistochemistry to confirm results in research and diagnostic testing. Specificity of antibodies employed for immunohistochemical studies is of critical importance. Therefore, the use of western blotting is imperative to address the specificity of antibodies with/without siRNA knockdown of proteins of interest or with the use of peptide inhibitors to inhibit the binding of specific antibodies to the target protein. In spite of its overall simplicity, western blotting or protein blotting is a powerful procedure for immunodetection of proteins, especially those that are of low abundance, following electrophoretic separation. The usefulness of this procedure stems from its ability to provide simultaneous resolution of multiple immunogenic antigens within a sample for detection by specific antibodies. Protein blotting has evolved greatly over the last few decades, and researchers have a variety of ways and means to carry out this procedure to validate antibodies for immunohistochemistry.
Collapse
Affiliation(s)
- Biji T Kurien
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Department of Veterans Affairs Medical Center, Oklahoma City, OK, USA.
| | - R Hal Scofield
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Department of Veterans Affairs Medical Center, Oklahoma City, OK, USA
| |
Collapse
|
5
|
Turpin J, Frumence E, El Safadi D, Meilhac O, Krejbich-Trotot P, Viranaïcken W. Improvement of immunodetection of the transcription factor C/EBP homologous protein by western blot. Anal Biochem 2020; 601:113775. [PMID: 32416096 DOI: 10.1016/j.ab.2020.113775] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/04/2020] [Accepted: 05/09/2020] [Indexed: 01/20/2023]
Abstract
Accumulation of misfolded proteins within the endoplasmic reticulum (ER) induces an unfolded protein response (UPR) that either restores homeostasis or triggers apoptosis in case of adaptation failure. The three activated branches of UPR lead to IRE1-, PERK- and ATF6- dependent transcriptional induction of the gene encoding the transcription factor C/EBP homologous protein (CHOP) which plays an important role in apoptosis induction. In conventional immunoblotting conditions, detection of CHOP is a difficult task. Using a fixation step, we have optimized the detection of CHOP and this method provides a valuable tool to decipher CHOP involvement in UPR.
Collapse
Affiliation(s)
- Jonathan Turpin
- Université de La Réunion, INSERM UMR 1187, CNRS 9192, IRD 249, Processus Infectieux en Milieu Insulaire Tropical (PIMIT), Plateforme CYROI, 2, Rue Maxime Rivière, 97490, Sainte-Clotilde, Ile de La Réunion, France
| | - Etienne Frumence
- Université de La Réunion, INSERM UMR 1187, CNRS 9192, IRD 249, Processus Infectieux en Milieu Insulaire Tropical (PIMIT), Plateforme CYROI, 2, Rue Maxime Rivière, 97490, Sainte-Clotilde, Ile de La Réunion, France
| | - Daed El Safadi
- Université de La Réunion, INSERM UMR 1187, CNRS 9192, IRD 249, Processus Infectieux en Milieu Insulaire Tropical (PIMIT), Plateforme CYROI, 2, Rue Maxime Rivière, 97490, Sainte-Clotilde, Ile de La Réunion, France
| | - Olivier Meilhac
- Université de La Réunion, INSERM UMR 1188, Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), Plateforme CYROI, 2, Rue Maxime Rivière, 97490, Sainte-Clotilde, Ile de La Réunion, France; CHU de La Réunion, Saint-Denis, France
| | - Pascale Krejbich-Trotot
- Université de La Réunion, INSERM UMR 1187, CNRS 9192, IRD 249, Processus Infectieux en Milieu Insulaire Tropical (PIMIT), Plateforme CYROI, 2, Rue Maxime Rivière, 97490, Sainte-Clotilde, Ile de La Réunion, France.
| | - Wildriss Viranaïcken
- Université de La Réunion, INSERM UMR 1187, CNRS 9192, IRD 249, Processus Infectieux en Milieu Insulaire Tropical (PIMIT), Plateforme CYROI, 2, Rue Maxime Rivière, 97490, Sainte-Clotilde, Ile de La Réunion, France.
| |
Collapse
|
6
|
Arvin NE, Dawod M, Lamb DT, Anderson JP, Furtaw MD, Kennedy RT. Fast Immunoassay for Microfluidic Western Blotting by Direct Deposition of Reagents onto Capture Membrane. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2020; 12:1606-1616. [PMID: 32661464 PMCID: PMC7357712 DOI: 10.1039/d0ay00207k] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Western blotting is a widely used protein assay platform, but the technique requires long analysis times and multiple manual steps. Microfluidic systems are currently being explored for increased automation and reduction of analysis times, sample volumes, and reagent consumption for western blots. Previous work has demonstrated that proteins separated by microchip electrophoresis can be captured on membranes by dragging the microchip outlet across the membrane. This process reduces the separation and transfer time of a western blot to a few minutes. To further improve the speed and miniaturization of a complete western blot, a microscale immunoassay with direct deposition of immunoassay reagents has been developed. Flow deposition of antibodies is used to overcome diffusion limited binding kinetics so that the entire immunoassay can be completed in 1 h with detection sensitivity comparable to incubation steps requiring 20 h. The use of low microliter/min flow rates with antibody reagents applied directly and locally to the membrane where the target proteins have been captured, reduced antibody consumption ~30-fold. The complete western blot was applied to the detection of GAPDH and β-Tubulin from A431 cell lysate.
Collapse
Affiliation(s)
- Natalie E. Arvin
- Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, Michigan 48109, United States
| | - Mohamed Dawod
- Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, Michigan 48109, United States
- Vaccine Analytical R&D, Merck Research Laboratories, 770 Sumneytown Pike, West Point, Pennsylvania 19486, United States
| | - Don T. Lamb
- LI-COR Biosciences, 4647 Superior St., Lincoln, Nebraska 68504, United States
| | - Jon P. Anderson
- LI-COR Biosciences, 4647 Superior St., Lincoln, Nebraska 68504, United States
| | - Michael D. Furtaw
- LI-COR Biosciences, 4647 Superior St., Lincoln, Nebraska 68504, United States
| | - Robert T. Kennedy
- Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, Michigan 48109, United States
- Department of Pharmacology, University of Michigan, 1150 W. Medical Center Dr., Ann Arbor, Michigan 48109, United States
- Corresponding author: Robert T. Kennedy, , Tel: 734-615-4363, Fax: 745-615-6462
| |
Collapse
|
7
|
Transcript levels for extracellular matrix proteins are altered in MK5-deficient cardiac ventricular fibroblasts. J Mol Cell Cardiol 2019; 132:164-177. [DOI: 10.1016/j.yjmcc.2019.05.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 03/22/2019] [Accepted: 05/15/2019] [Indexed: 11/22/2022]
|
8
|
Cerebrospinal fluid BDNF pro-peptide levels in major depressive disorder and schizophrenia. J Psychiatr Res 2019; 113:190-198. [PMID: 30986693 DOI: 10.1016/j.jpsychires.2019.03.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 03/21/2019] [Accepted: 03/22/2019] [Indexed: 01/06/2023]
Abstract
The role of brain-derived neurotrophic factor (BDNF) and its related molecules has been extensively studied in the context of psychiatric disorders. In the present study, we focused on the newly identified BDNF pro-peptide, which is generated together with mature BDNF by proteolytic processing of their precursor, proBDNF. Here, we report, for the first time, that BDNF pro-peptide is present in human cerebrospinal fluid (CSF) and quantifiable by western blotting. We measured CSF BDNF pro-peptide levels in 27 patients with schizophrenia, 18 patients with major depressive disorder (MDD), and 27 healthy controls matched for age, sex, and ethnicity (Japanese). The ratio of the BDNF pro-peptide level to the total protein level in MDD patients was significantly lower than that in controls (Kruskal-Wallis with Dunn's multiple comparisons test; p = 0.046). When men and women were examined separately, males with MDD had a significantly lower BDNF pro-peptide/protein ratio than male controls (p = 0.047); this difference was not found in female subjects. The ratio tended to be lower in male schizophrenia patients (p = 0.10). Although we tried to measure the levels of mature BDNF in CSF, they were below the limit of detection of the ELISA and multiple analyte profiling technology. Taken together, the results suggest that reduced CSF BDNF pro-peptide levels are associated with MDD, particularly in males. Further studies involving a larger sample size are warranted.
Collapse
|
9
|
Abstract
Western blotting is the most extensively used technique for the identification and characterisation of proteins and their expression levels. One of the major issues with this technique is the loss of proteins from the blotted membrane during the incubation and washing steps, which affects its sensitivity and reproducibility. Here, we have optimised the fixation conditions for immunoblotting and lectin blotting on electroblotted polyvinylidene difluoride and nitrocellulose membranes, using a combination of organic solvents and heating. Loss of proteins from polyvinylidene difluoride membranes was greatly reduced using this approach, the intensity of lectin blotting and immunoblotting was shown to increase 2.8- to 15-fold and 1.8- to 16-fold, respectively, compared with that samples without treated. Using the optimised method, cystic fibrosis transmembrane regulator and hypoxia-inducible factor 1, two difficult-to-analyse proteins with important physiological and pathological roles, were effectively detected. Additionally, it may help the identification of novel diagnostic markers for prostate cancer.
Collapse
|
10
|
Thakrar FJ, Singh SP. Catalytic, thermodynamic and structural properties of an immobilized and highly thermostable alkaline protease from a haloalkaliphilic actinobacteria, Nocardiopsis alba TATA-5. BIORESOURCE TECHNOLOGY 2019; 278:150-158. [PMID: 30685619 DOI: 10.1016/j.biortech.2019.01.058] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/11/2019] [Accepted: 01/12/2019] [Indexed: 06/09/2023]
Abstract
A highly thermostable protease from a haloalkaliphilic actinobacteria was immobilized employing 5 different approaches on 24 carriers. On immobilization, the activation energy and deactivation rate constant decreased, which makes the immobilized protease favourable for applications. Similarly, pH and temperature stability was enhanced, while the Vmax and Km changed upon immobilization. The immobilized enzyme had greater stability in various metal ions and detergents. The structural topography of the immobilized enzyme elucidated by the FTIR suggested the function of aliphatic amines, alkenes and esters since amide I and II bands were affected. Noticeable decrease in the Amide A band suggests interaction between the immobilization carriers and -NH groups of the protease molecule. The suitability of the immobilized protease was established by designing a continuous flow enzyme bioreactor, displaying the enzyme half-life of 916.15 min at 60 °C. The enzyme reactor was highly efficient in the treatment of the municipal and dairy wastewater.
Collapse
Affiliation(s)
- Foram J Thakrar
- UGC-CAS Department of Biosciences, Saurashtra University, Rajkot 360 005, Gujarat, India
| | - Satya P Singh
- UGC-CAS Department of Biosciences, Saurashtra University, Rajkot 360 005, Gujarat, India.
| |
Collapse
|
11
|
Modified Western blotting for insulin and other diabetes-associated peptide hormones. Sci Rep 2017; 7:6949. [PMID: 28761041 PMCID: PMC5537366 DOI: 10.1038/s41598-017-04456-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 05/03/2017] [Indexed: 12/16/2022] Open
Abstract
Now, the quantification of proinsulin/insulin contents within organisms tends to be evaluated only by enzyme-linked immunosorbent assay (ELISA), although assessing the adequacy of results by some quantification method is important. Remarkably, few scientific papers use detection by Western blotting (WB), another immunological assay, of proinsulin/insulin. We found two problems with quantification of insulin and proinsulin by general WB: the shape of an insulin band in gel electrophoresis is distorted, and the retention potency to a blotting membrane of the peptide hormones (mainly insulin) is low. We solved the first problem by optimizing the sodium dodecyl sulfate concentration in the sample buffer and the second problem by glutaraldehyde fixation following treatment with a blocking solution for a short time. The improvements were confirmed by quantification of proinsulin/insulin in standards, MIN6c4 cell lysates, and MIN6c4 culture supernatants. Furthermore, we showed that the modified WB is applicable to other diabetes-associated peptide hormones: insulin analogs, glucagon, GLP-1s, somatostatins, ghrelins, and pancreatic polypeptide. Our data showed that the modified WB can contribute to qualitative or quantitative analyses of diabetes-associated peptides by providing analytical information based on electrophoresis, although ELISA, which is an almost exclusive method in the quantification of peptide hormones, supplies only numerical data.
Collapse
|
12
|
Zanin JP, Unsain N, Anastasia A. Growth factors and hormones pro-peptides: the unexpected adventures of the BDNF prodomain. J Neurochem 2017; 141:330-340. [PMID: 28218971 DOI: 10.1111/jnc.13993] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 02/08/2017] [Accepted: 02/13/2017] [Indexed: 12/26/2022]
Abstract
Most growth factors and hormones are synthesized as pre-pro-proteins which are processed to the biologically active mature protein. The pre- and prodomains are cleaved from the precursor protein in the secretory pathway or, in some cases, extracellularly. The canonical functions of these prodomains are to assist in folding and stabilization of the mature domain, to direct intra and extracellular localization, to facilitate storage, and to regulate bioavailability of their mature counterpart. Recently, exciting evidence has revealed that prodomains of certain growth factors, after cleaved from the precursor pro-protein, can act as independent active signaling molecules. In this review, we discuss the various classical functions of prodomains, and the biological consequences of these pro-peptides acting as ligands. We will focus our attention on the brain-derived neurotrophic factor prodomain (pBDNF), which has been recently described as a novel secreted ligand influencing neuronal morphology and physiology.
Collapse
Affiliation(s)
- Juan Pablo Zanin
- Department of Biological Sciences, Rutgers University, Newark, New Jersey, USA
| | - Nicolás Unsain
- Instituto de Investigación Médica Mercedes y Martin Ferreyra, (INIMEC-CONICET-Universidad Nacional de Córdoba), Córdoba, Argentina
| | - Agustin Anastasia
- Instituto de Investigación Médica Mercedes y Martin Ferreyra, (INIMEC-CONICET-Universidad Nacional de Córdoba), Córdoba, Argentina
| |
Collapse
|
13
|
Kurien BT, Scofield RH. Validating Antibody Specificities for Immunohistochemistry by Protein Blotting Methods. Methods Mol Biol 2017; 1554:61-73. [PMID: 28185183 DOI: 10.1007/978-1-4939-6759-9_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Immunoblotting has been used in conjunction with other important antibody based detection methods like enzyme linked immunosorbent assay and immunohistochemistry to provide confirmation of results both in research and diagnostic testing. Specificity of antibodies employed for immunohistochemical studies is of critical importance and therefore the use of western blotting is imperative to address specificity of antibodies. In spite of its overall simplicity, western blotting or protein blotting is a powerful procedure for immunodetection of proteins, especially those that are of low abundance, following electrophoretic separation. The usefulness of this procedure stems from its ability to provide simultaneous resolution of multiple immunogenic antigens within a sample for detection by specific antibodies. Protein blotting has evolved greatly over the last few decades and researchers have a variety of ways and means to carry out this procedure to validate antibodies for immunohistochemistry.
Collapse
Affiliation(s)
- Biji T Kurien
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA.
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
- Department of Veterans Affairs Medical Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
| | - R Hal Scofield
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
- Department of Veterans Affairs Medical Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| |
Collapse
|
14
|
Wu J, Zhu J, He C, Xiao Z, Ye J, Li Y, Chen A, Zhang H, Li X, Lin L, Zhao Y, Zheng J, Xiao J. Comparative Study of Heparin-Poloxamer Hydrogel Modified bFGF and aFGF for in Vivo Wound Healing Efficiency. ACS APPLIED MATERIALS & INTERFACES 2016; 8:18710-18721. [PMID: 27384134 DOI: 10.1021/acsami.6b06047] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Wound therapy remains a clinical challenge. Incorporation of growth factors (GFs) into heparin-functionalized polymer hydrogel is considered as a promising strategy to improve wound healing efficiency. However, different GFs incorporation into the same heparin-based hydrogels often lead to different wound healing effects, and the underlying GF-induced wound healing mechanisms still remain elusive. Herein, we developed a thermos-sensitive heparin-poloxamer (HP) hydrogel to load and deliver different GFs (aFGF and bFGF) for wound healing in vivo. The resulting GFs-based hydrogels with and without HP hydrogels were systematically evaluated and compared for their wound healing efficiency by extensive in vivo tests, including wound closure rate, granulation formation, re-epithelization, cell proliferation, collagen, and angiogenesis expressions. While all GFs-based dressings with and without HP hydrogels exhibited better wound healing efficacy than controls, both HP-aFGF and HP-bFGF hydrogels demonstrated their superior healing activity to improve wound closure, granulation formation, re-epithelization, and blood vessel density by up-regulation of PCNA proliferation and collagen synthesis, as compared to GF dressings alone. More importantly, HP-aFGF dressings exhibited the higher healing efficacy than HP-bFGF dressings, indicating that different a/bFGF surface properties lead to different binding and release behaviors in HP hydrogels, both of which will affect different wound healing efficiency. On the basis of experimental observations, the working mechanisms of different healing effects of HP-GFs on full skin removal wound were proposed. This work provides different views of the design and development of an effective hydrogel-based delivery system for GFs toward rapid wound healing.
Collapse
Affiliation(s)
- Jiang Wu
- School of Pharmaceutical Sciences, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical University , Wenzhou, Zhejiang 325035, China
| | - Jingjing Zhu
- School of Pharmaceutical Sciences, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical University , Wenzhou, Zhejiang 325035, China
| | - Chaochao He
- School of Pharmaceutical Sciences, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical University , Wenzhou, Zhejiang 325035, China
| | - Zecong Xiao
- School of Pharmaceutical Sciences, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical University , Wenzhou, Zhejiang 325035, China
| | - Jingjing Ye
- School of Pharmaceutical Sciences, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical University , Wenzhou, Zhejiang 325035, China
| | - Yi Li
- School of Pharmaceutical Sciences, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical University , Wenzhou, Zhejiang 325035, China
| | - Anqi Chen
- School of Pharmaceutical Sciences, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical University , Wenzhou, Zhejiang 325035, China
| | - Hongyu Zhang
- School of Pharmaceutical Sciences, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical University , Wenzhou, Zhejiang 325035, China
| | - Xiaokun Li
- School of Pharmaceutical Sciences, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical University , Wenzhou, Zhejiang 325035, China
| | - Li Lin
- School of Pharmaceutical Sciences, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical University , Wenzhou, Zhejiang 325035, China
| | - Yingzheng Zhao
- School of Pharmaceutical Sciences, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical University , Wenzhou, Zhejiang 325035, China
| | - Jie Zheng
- Department of Chemical and Biomolecular Engineering, The University of Akron , Akron, Ohio 44325, United States
| | - Jian Xiao
- School of Pharmaceutical Sciences, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical University , Wenzhou, Zhejiang 325035, China
| |
Collapse
|
15
|
Wiśniewski JR, Mann M. A Proteomics Approach to the Protein Normalization Problem: Selection of Unvarying Proteins for MS-Based Proteomics and Western Blotting. J Proteome Res 2016; 15:2321-6. [PMID: 27297043 DOI: 10.1021/acs.jproteome.6b00403] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Proteomics and other protein-based analysis methods such as Western blotting all face the challenge of discriminating changes in the levels of proteins of interest from inadvertent changes in the amount loaded for analysis. Mass-spectrometry-based proteomics can now estimate the relative and absolute amounts of thousands of proteins across diverse biological systems. We reasoned that this new technology could prove useful for selection of very stably expressed proteins that could serve as better loading controls than those traditionally employed. Large-scale proteomic analyses of SDS lysates of cultured cells and tissues revealed deglycase DJ-1 as the protein with the lowest variability in abundance among different cell types in human, mouse, and amphibian cells. The protein constitutes 0.069 ± 0.017% of total cellular protein and occurs at a specific concentration of 34.6 ± 8.7 pmol/mg of total protein. Since DJ-1 is ubiquitous and therefore easily detectable with several peptides, it can be helpful in normalization of proteomic data sets. In addition, DJ-1 appears to be an advantageous loading control for Western blot that is superior to those used commonly used, allowing comparisons between tissues and cells originating from evolutionarily distant vertebrate species. Notably, this is not possible by the detection and quantitation of housekeeping proteins, which are often used in the Western blot technique. The approach introduced here can be applied to select the most appropriate loading controls for MS-based proteomics or Western blotting in any biological system.
Collapse
Affiliation(s)
- Jacek R Wiśniewski
- Biochemical Proteomics Group, ‡Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry , 82152 Martinsried, Germany
| | - Matthias Mann
- Biochemical Proteomics Group, ‡Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry , 82152 Martinsried, Germany
| |
Collapse
|
16
|
Chmielewska M, Symonowicz K, Pula B, Owczarek T, Podhorska-Okolow M, Ugorski M, Dziegiel P. Expression of metallothioneins I and II in kidney of doxorubicin-treated rats. ACTA ACUST UNITED AC 2015; 67:297-303. [DOI: 10.1016/j.etp.2015.01.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 12/12/2014] [Accepted: 01/29/2015] [Indexed: 10/24/2022]
|
17
|
A novel PKD2L1 C-terminal domain critical for trimerization and channel function. Sci Rep 2015; 5:9460. [PMID: 25820328 PMCID: PMC4377555 DOI: 10.1038/srep09460] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 03/06/2015] [Indexed: 11/08/2022] Open
Abstract
As a transient receptor potential (TRP) superfamily member, polycystic kidney disease 2-like-1 (PKD2L1) is also called TRPP3 and has similar membrane topology as voltage-gated cation channels. PKD2L1 is involved in hedgehog signaling, intestinal development, and sour tasting. PKD2L1 and PKD1L3 form heterotetramers with 3:1 stoichiometry. C-terminal coiled-coil-2 (CC2) domain (G699-W743) of PKD2L1 was reported to be important for its trimerization but independent studies showed that CC2 does not affect PKD2L1 channel function. It thus remains unclear how PKD2L1 proteins oligomerize into a functional channel. By SDS-PAGE, blue native PAGE and mutagenesis we here identified a novel C-terminal domain called C1 (K575-T622) involved in stronger homotrimerization than the non-overlapping CC2, and found that the PKD2L1 N-terminus is critical for dimerization. By electrophysiology and Xenopus oocyte expression, we found that C1, but not CC2, is critical for PKD2L1 channel function. Our co-immunoprecipitation and dynamic light scattering experiments further supported involvement of C1 in trimerization. Further, C1 acted as a blocking peptide that inhibits PKD2L1 trimerization as well as PKD2L1 and PKD2L1/PKD1L3 channel function. Thus, our study identified C1 as the first PKD2L1 domain essential for both PKD2L1 trimerization and channel function, and suggest that PKD2L1 and PKD2L1/PKD1L3 channels share the PKD2L1 trimerization process.
Collapse
|
18
|
Gorr TA, Vogel J. Western blotting revisited: Critical perusal of underappreciated technical issues. Proteomics Clin Appl 2015; 9:396-405. [DOI: 10.1002/prca.201400118] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 12/19/2014] [Accepted: 01/14/2015] [Indexed: 01/17/2023]
Affiliation(s)
- Thomas A. Gorr
- Institute of Veterinary Physiology; Vetsuisse Faculty; University of Zürich; Zürich Switzerland
- Center for Pediatrics and Adolescent Medicine; Clinic IV: Division of Pediatric Hematology and Oncology; University Medical Center Freiburg; Freiburg Germany
| | - Johannes Vogel
- Institute of Veterinary Physiology; Vetsuisse Faculty; University of Zürich; Zürich Switzerland
| |
Collapse
|
19
|
Abstract
Western blotting is an important procedure for the immunodetection of proteins, particularly proteins that are of low abundance. This process involves the transfer of protein patterns from gel to microporous membrane. Electrophoretic as well as non-electrophoretic transfer of proteins to membranes was first described in 1979. Protein blotting has evolved greatly since the inception of this protocol, allowing protein transfer to be accomplished in a variety of ways.
Collapse
Affiliation(s)
- Biji T Kurien
- Arthritis and Clinical Immunology, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK, 73104, USA,
| | | |
Collapse
|
20
|
Anastasia A, Deinhardt K, Chao MV, Will NE, Irmady K, Lee FS, Hempstead BL, Bracken C. Val66Met polymorphism of BDNF alters prodomain structure to induce neuronal growth cone retraction. Nat Commun 2014; 4:2490. [PMID: 24048383 PMCID: PMC3820160 DOI: 10.1038/ncomms3490] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 08/21/2013] [Indexed: 12/29/2022] Open
Abstract
A common single-nucleotide polymorphism (SNP) in the human brain-derived neurotrophic factor (BDNF) gene results in a Val66Met substitution in the BDNF prodomain region. This SNP is associated with alterations in memory and with enhanced risk to develop depression and anxiety disorders in humans. Here we show that the isolated BDNF prodomain is detected in the hippocampus and that it can be secreted from neurons in an activity-dependent manner. Using nuclear magnetic resonance spectroscopy and circular dichroism, we find that the prodomain is intrinsically disordered, and the Val66Met substitution induces structural changes. Surprisingly, application of Met66 (but not Val66) BDNF prodomain induces acute growth cone retraction and a decrease in Rac activity in hippocampal neurons. Expression of p75(NTR) and differential engagement of the Met66 prodomain to the SorCS2 receptor are required for this effect. These results identify the Met66 prodomain as a new active ligand, which modulates neuronal morphology.
Collapse
Affiliation(s)
- Agustin Anastasia
- Department of Medicine, Weill Cornell Medical College of Cornell University, 1300 York Avenue, New York, New York 10065, USA
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Dieni S, Matsumoto T, Dekkers M, Rauskolb S, Ionescu MS, Deogracias R, Gundelfinger ED, Kojima M, Nestel S, Frotscher M, Barde YA. BDNF and its pro-peptide are stored in presynaptic dense core vesicles in brain neurons. ACTA ACUST UNITED AC 2012; 196:775-88. [PMID: 22412021 PMCID: PMC3308691 DOI: 10.1083/jcb.201201038] [Citation(s) in RCA: 248] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Contrasting with the long-established retrograde model for neurotrophin function, specific immunohistochemical localization of brain-derived neurotrophic factor in the central nervous system supports the alternative model of presynaptic localization and anterograde function. Although brain-derived neurotrophic factor (BDNF) regulates numerous and complex biological processes including memory retention, its extremely low levels in the mature central nervous system have greatly complicated attempts to reliably localize it. Using rigorous specificity controls, we found that antibodies reacting either with BDNF or its pro-peptide both stained large dense core vesicles in excitatory presynaptic terminals of the adult mouse hippocampus. Both moieties were ∼10-fold more abundant than pro-BDNF. The lack of postsynaptic localization was confirmed in Bassoon mutants, a seizure-prone mouse line exhibiting markedly elevated levels of BDNF. These findings challenge previous conclusions based on work with cultured neurons, which suggested activity-dependent dendritic synthesis and release of BDNF. They instead provide an ultrastructural basis for an anterograde mode of action of BDNF, contrasting with the long-established retrograde model derived from experiments with nerve growth factor in the peripheral nervous system.
Collapse
Affiliation(s)
- Sandra Dieni
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
The Loss of HIF1α Leads to Increased Susceptibility to Cadmium-Chloride-Induced Toxicity in Mouse Embryonic Fibroblasts. J Toxicol 2011; 2011:391074. [PMID: 21811500 PMCID: PMC3147003 DOI: 10.1155/2011/391074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 04/13/2011] [Accepted: 05/05/2011] [Indexed: 11/30/2022] Open
Abstract
Wild-type and HIF1α −/− MEF cells were used to determine the role of HIF1α in cadmium-induced toxicity. Cadmium treatment did not affect HIF1-mediated transcription but led to caspase activation and apoptotic cell death in wild-type and HIF1α −/− cells. Cadmium-induced cell death, however, was significantly higher in HIF1α −/− cells as compared to their wild-type counterparts. Increased cell death in the HIF1α −/− cells was correlated with lower metallothionein protein, elevated levels of reactive oxygen species, and decreased superoxide dismutase enzyme activity. The total and oxidized glutathione levels, and, correspondingly, lipid peroxidation levels were elevated in the null cells compared to wild-type cells, indicating increased antioxidant demand and greater oxidative stress. Overall, the results suggest that basal levels of HIF1α play a protective role against cadmium-induced cytotoxicity in mouse embryonic fibroblasts by maintaining metallothionein and antioxidant activity levels.
Collapse
|
23
|
Affiliation(s)
- Reiner Westermeier
- SERVA Electrophoresis GmbH, Carl-Benz-Strasse 7, D-69115 Heidelberg, Germany
| |
Collapse
|
24
|
Kurien BT, Dorri Y, Dillon S, Dsouza A, Scofield RH. An overview of Western blotting for determining antibody specificities for immunohistochemistry. Methods Mol Biol 2011; 717:55-67. [PMID: 21370024 DOI: 10.1007/978-1-61779-024-9_3] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Despite its overall simplicity, protein blotting or Western blotting has been proven to be a powerful procedure for the immunodetection of proteins, especially those that are of low abundance, following electrophoresis. The usefulness of this procedure stems from its ability to provide simultaneous resolution of multiple immunogenic antigens within a sample for detection by specific antibodies. Protein blotting has evolved greatly since its inception and researchers have a variety of ways and means to carry out this transfer. This procedure is used in combination with other important antibody-based detection methods such as enzyme-linked immunosorbant assay and immunohistochemistry to provide confirmation of results both in research and diagnostic testing. Specificity of antibodies used for immunohistochemistry is of critical importance and therefore Western blot is a "must" to address antibodies' specificity.
Collapse
Affiliation(s)
- Biji T Kurien
- Arthritis and Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.
| | | | | | | | | |
Collapse
|
25
|
MacPhee DJ. Methodological considerations for improving Western blot analysis. J Pharmacol Toxicol Methods 2009; 61:171-7. [PMID: 20006725 DOI: 10.1016/j.vascn.2009.12.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Accepted: 12/07/2009] [Indexed: 10/20/2022]
Abstract
The need for a technique that could allow the determination of antigen specificity of antisera led to the development of a method that allowed the production of a replica of proteins, which had been separated electrophoretically on polyacrylamide gels, on to a nitrocellulose membrane. This method was coined Western blotting and is very useful to study the presence, relative abundance, relative molecular mass, post-translational modification, and interaction of specific proteins. As a result it is utilized routinely in many fields of scientific research such as chemistry, biology and biomedical sciences. This review serves to touch on some of the methodological conditions that should be considered to improve Western blot analysis, particularly as a guide for graduate students but also scientists who wish to continue adapting this now fundamental research tool.
Collapse
Affiliation(s)
- Daniel J MacPhee
- Division of BioMedical Sciences, Faculty of Medicine, Health Sciences Centre, Memorial University of Newfoundland, St. John's, NL, Canada A1B 3V6.
| |
Collapse
|
26
|
Abstract
Protein blotting is a powerful and important procedure for the immunodetection of proteins following electrophoresis, particularly proteins that are of low abundance. Since the inception of the protocol for protein transfer from an electrophoresed gel to a membrane in 1979, protein blotting has evolved greatly. The scientific community is now confronted with a variety of ways and means to carry out this transfer.
Collapse
|
27
|
Melnikov SV, Evstafieva AG, Vartapetian AB. Interaction with Keap1 does not lead to ubiquitination and degradation of prothymosin α. Mol Biol 2007. [DOI: 10.1134/s0026893307050123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
28
|
Duchesne L, Fernig DG. Silver and gold nanoparticle-coated membranes for femtomole detection of small proteins and peptides by Dot and Western blot. Anal Biochem 2006; 362:287-9. [PMID: 17241607 DOI: 10.1016/j.ab.2006.12.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2006] [Revised: 12/05/2006] [Accepted: 12/12/2006] [Indexed: 11/21/2022]
Affiliation(s)
- Laurence Duchesne
- Centre for Nanoscale Science, School of Biological Sciences, Bioscience Building, University of Liverpool, Liverpool, UK.
| | | |
Collapse
|
29
|
Kobayashi T, Wang T, Maezawa M, Kobayashi M, Ohnishi S, Hatanaka K, Hige S, Shimizu Y, Kato M, Asaka M, Tanaka J, Imamura M, Hasegawa K, Tanaka Y, Brachmann RK. Overexpression of the oncoprotein prothymosin alpha triggers a p53 response that involves p53 acetylation. Cancer Res 2006; 66:3137-44. [PMID: 16540664 DOI: 10.1158/0008-5472.can-05-2112] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Activation of the tumor suppressor protein p53 is a critical cellular response to various stress stimuli and to inappropriate activity of growth-promoting proteins, such as Myc, Ras, E2F, and beta-catenin. Protein stability and transcriptional activity of p53 are modulated by protein-protein interactions and post-translational modifications, including acetylation. Here, we show that inappropriate activity of prothymosin alpha (PTMA), an oncoprotein overexpressed in human cancers, triggers a p53 response. Overexpression of PTMA enhanced p53 transcriptional activity in reporter gene assays for p53 target gene promoters hdm2, p21, and cyclin G. Overexpressed PTMA resulted in increased mRNA and protein levels for endogenous p53 target genes, hdm2 and p21, and in growth suppression. In contrast, reduction of endogenous PTMA through RNA interference decreased p53 transcriptional activity. Histone acetyltransferases (HATs) act as p53 coactivators and acetylate p53. PTMA, known to interact with HATs, led to increased levels of acetylated p53. PTMA did not increase the transcriptional activity of an acetylation-deficient p53 mutant, suggesting that p53 acetylation is an indispensable part of the p53 response to PTMA. Chromatin immunoprecipitation assays showed that excess PTMA associates with the p21 promoter and results in increased levels of acetylated p53 at the p21 promoter. Our findings indicate that overexpressed PTMA elicits a p53 response that involves p53 acetylation.
Collapse
Affiliation(s)
- Takahiko Kobayashi
- Hokkaido University Medical Hospital, Primary Care Medicine, Sapporo, Japan.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Lai JKC, Cheng CHK, Ko WH, Leung PS. Ghrelin system in pancreatic AR42J cells: its ligand stimulation evokes calcium signalling through ghrelin receptors. Int J Biochem Cell Biol 2005; 37:887-900. [PMID: 15694847 DOI: 10.1016/j.biocel.2004.11.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2003] [Revised: 09/14/2004] [Accepted: 11/15/2004] [Indexed: 02/01/2023]
Abstract
Ghrelin is an endogenous ligand for the growth hormone secretagogue receptor. The presence of ghrelin in pancreatic islet cells has been previously reported and it is known to increase the [Ca2+]i in (-cells, affecting insulin secretion. However, evidence for the existence of the ghrelin system and its calcium signalling pathway in the exocrine pancreas remains unclear. Thus this study aims, first, to investigate the expression of ghrelin and its receptor in pancreatic AR42J cells and, secondly, to elucidate its calcium signalling pathway. Our results showed that ghrelin and ghrelin receptor were consistently expressed in AR42J cells. Moreover, fluorescence imaging showed that cholecystokinin-8, ghrelin and growth hormone-releasing hexapeptide stimulate [Ca2+]i in AR42J cells in a dose-dependent manner. Ghrelin and the hexapeptide produced a biphasic elevation in [Ca2+]i with an initial transient increase, followed by a sustained plateau. In the presence of (D-Lys3)-GHRP-6, the [Ca2+]i evoked by ghrelin was suppressed. In the absence of extracellular Ca2+, the transient phase of the ghrelin response was maintained but greatly diminished while the plateau phase was completely abolished. Pretreatment with 2-aminoethoxydiphenyl borate and xestospongin C abolished the transient phase and inhibited the sustained phase of the ghrelin response. The stimulatory effect of ghrelin was also blocked by nifedipine. These results indicate that ligand stimulation of the ghrelin receptor could lead to a biphasic [Ca2+]i mobilization in these cells. These data suggests the presence of a ghrelin system in pancreatic AR42J cells. In addition, its roles in exocrine function are implicated in the pancreas.
Collapse
Affiliation(s)
- Jan Kit Ching Lai
- Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, PR China
| | | | | | | |
Collapse
|
31
|
Boumba VA, Seferiadis K. Rabbit anti-HMG-17 antibodies recognize similar epitopes on the HMG-17 molecule as lupus autoantibodies. Relation with histone H1 defined epitopes. J Pept Sci 2002; 8:683-94. [PMID: 12523645 DOI: 10.1002/psc.429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
HMG-17 is a nucleosomal protein which is an immune target of autoantibodies in systemic lupus erythematosus (SLE) and other autoimmune diseases. Autoantibody production in SLE is believed to result from autoantigen specific immune stimulation and subsequently, it is expected that antigenic determinants recognized by SLE autoantibodies and induced antibodies by immunization are quite similar. To examine this issue, rabbits were immunized with purified HMG-17. The produced antiserum showed cross reactivity on blots and in inhibition ELISA with histone H1, even after its affinity purification with immobilized HMG-17. Finally, purification of the antiserum over H1 absorbed on nitrocellulose membrane produced specific anti-HMG-17 antibodies in the supernatant and anti-HMG-17/H1 antibodies that were bound to H1. SLE sera positive for HMG-17 had also cross reactivity with H1, and following the same procedure as before we received HMG-17 specific SLE autoantibodies and anti-HMG-17/H1 autoantibodies. Using the multipin epitope mapping technology, 19 overlapping 15-mer HMG-17 peptides and six 15-peptides, corresponding to known epitopes of histone H1, were synthesized. Four major epitopes were identified on the HMG-17 molecule, reactive with induced anti-HMG-17 antibodies, and these were the same as major autoepitopes In SLE. The sequence 25-51 of HMG-17, part of its DNA-binding domain, was recognized by the anti-HMG-17/H1 antibodies that were bound to H1. These antibodies recognized also defined epitopes of H1. Our results show that SLE autoantibodies can be directed against the same or similar epitopes as do IgGs evoked during the active immunization of animals, and provide additional evidence that autosensitization with an autoantigen might be operative. The possibility that the same or similar epitopes are found on different molecules (in this study HMG-17 and H1) supports the fact that there are rules by which nature selects the most dominant immunodeterminant to a given protein, which often represents functional or structural sites in the autoantigen.
Collapse
Affiliation(s)
- Vassiliki A Boumba
- Laboratory of Biological Chemistry, University of Ioannina, Medical School, 451 10 Ioannina, Greece
| | | |
Collapse
|
32
|
Thorne RG, Frey WH. Delivery of neurotrophic factors to the central nervous system: pharmacokinetic considerations. Clin Pharmacokinet 2002; 40:907-46. [PMID: 11735609 DOI: 10.2165/00003088-200140120-00003] [Citation(s) in RCA: 364] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Neurotrophic factors are proteins with considerable potential in the treatment of central nervous system (CNS) diseases and traumatic injuries. However, a significant challenge to their clinical use is the difficulty associated with delivering these proteins to the CNS. Neurotrophic factors are hydrophilic, typically basic, monomeric or dimeric proteins, mostly in the size range of 5 to 30 kDa. Neurotrophic factors potently support the development, growth and survival of neurons, eliciting biological effects at concentrations in the nanomolar to femtomolar range. They are not orally bioavailable and the blood-brain and blood-cerebrospinal fluid barriers severely limit their ability to enter into and act on sites in the CNS following parenteral systemic routes of administration. Most neurotrophic factors have short in vivo half-lives and poor pharmacokinetic profiles. Their access to the CNS is restricted by rapid enzymatic inactivation, multiple clearance processes, potential immunogenicity and sequestration by binding proteins and other components of the blood and peripheral tissues. The development of targeted drug delivery strategies for neurotrophic factors will probably determine their clinical effectiveness for CNS conditions. Achieving significant CNS target site concentrations while limiting systemic exposure and distribution to peripheral sites of action will lessen unwanted pleiotropic effects and toxicity. Local introduction of neurotrophic factors into the CNS intraparenchymally by direct injection/infusion or by implantation of delivery vectors such as polymer matrices or genetically modified cells yields the highest degree of targeting, but is limited by diffusion restrictions and invasiveness. Delivery of neurotrophic factors into the cerebrospinal fluid (CSF) following intracerebroventricular or intrathecal administration is less invasive and allows access to a much wider area of the CNS through CSF circulation pathways. However, diffusional and cellular barriers to penetration into surrounding CNS tissue and significant clearance of CSF into the venous and lymphatic circulation are also limiting. Unconventional delivery strategies such as intranasal administration may offer some degree of CNS targeting with minimal invasiveness. This review presents a summary of the neurotrophic factors and their indications for CNS disorders, their physicochemical characteristics and the different approaches that have been attempted or suggested for their delivery to the CNS. Future directions for further research such as the potential for CNS disease treatment utilising combinations of neurotrophic factors, displacement strategies, small molecule mimetics, chimaeric molecules and gene therapy are also discussed.
Collapse
Affiliation(s)
- R G Thorne
- Department of Pharmaceutics, University of Minnesota, Minneapolis, Minnesota, USA
| | | |
Collapse
|
33
|
Metzler DE, Metzler CM, Sauke DJ. Determining Structures and Analyzing Cells. Biochemistry 2001. [DOI: 10.1016/b978-012492543-4/50006-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
34
|
Guttenberger M. Chemical fixation avoids loss of low-molecular-weight polypeptides during silver staining in polyacrylamide gels. Anal Biochem 2001; 288:104-6. [PMID: 11141314 DOI: 10.1006/abio.2000.4857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- M Guttenberger
- Physiologische Okologie der Pflanzen, Botanisches Institut, Universität Tübingen, Auf der Morgenstelle 1, Tübingen, D-72076, Germany
| |
Collapse
|
35
|
Capetandes A, Di Salvo J, Ronan JJ, Thomas KA. Acidic fibroblast growth factor is present in the enteric nervous system of the large intestine. J Histochem Cytochem 2000; 48:407-14. [PMID: 10681394 DOI: 10.1177/002215540004800310] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Acidic fibroblast growth factor (aFGF) is a heparin binding protein that displays pleiotropic activity. The purpose of this study was to document the presence of the translated aFGF product, its mRNA, and its location in the colon. mRNA was extracted from bovine large intestine and reverse transcribed to cDNA. Nested-primer PCR was used to determine the presence of mRNA using primers homologous to the previously published bovine aFGF cDNA. Purification of translated aFGF was performed using an established HPLC protocol. Western blot analysis of the HPLC fractions was performed using two epitope-independent antibodies against aFGF. Immunohistochemistry employed these antibodies to determine the locus of aFGF expression. The nested-primer PCR product of predicted size was homologous to the published bovine aFGF mRNA sequence, as determined by DNA sequencing. Intestinal aFGF had a mass similar to bovine aFGF isolated from other tissues, and immunocrossreacted with two peptide-based, epitope-independent anti-aFGF antisera on Western blotting. Immunohistochemical analysis of large intestine using these two independent antisera localized aFGF within the myenteric plexus. These data demonstrate that aFGF is present within the myenteric plexus of the enteric nervous system.
Collapse
Affiliation(s)
- A Capetandes
- Department of Biomedical Sciences, Long Island University/CW Post Campus, Greenvale, New York, USA
| | | | | | | |
Collapse
|
36
|
Dutta B, Mukhopadhyay D, Roy N, Das G, Karande AA. Cloning, expression, purification, and immunocharacterization of placental protein-14. Protein Expr Purif 1998; 14:327-34. [PMID: 9882566 DOI: 10.1006/prep.1998.0961] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Human placental protein-14 (PP-14), a member of the lipocalin superfamily, shares homology at the level of the primary and secondary structures with bovine beta-lactoglobulin. It is the most prominent endometrial protein synthesized by the glandular cells of endometrium under estrogen priming and progesterone stimulation. The temporal and spatial expression of PP-14 in the female reproductive tract combined with its biological activities ex vivo suggest that this glycoprotein probably plays an essential physiological role in the regulation of fertilization, implantation, and maintenance of pregnancy. We proposed to elucidate the molecular mechanisms involved in the function of this protein. A prerequisite to such investigations on any protein is the availability of sufficient amounts of the same in a homogenous form. Therefore, recombinant DNA technology was employed. The PP-14 cDNA was obtained from the first-trimester endometrial tissue RNA by RT-PCR using unique primers. After confirming the identity of the gene, the protein was expressed in Escherichia coli and purified to homogeneity. The gene was also cloned and expressed in Pichia pastoris to obtain the protein product in a glycosylated form. The recombinant proteins were immunocharacterized using a cross-reactive antibody raised to bovine beta-lactoglobulin. Polyclonal antiserum raised to the E coli expressed PP-14 also bound to the native PP-14 from amniotic fluid suggesting that recombinant PP-14 may be exploited to elucidate functional aspects of the protein.
Collapse
Affiliation(s)
- B Dutta
- Department of Biochemistry, Indian Institute of Science, Bangalore, 560 012
| | | | | | | | | |
Collapse
|
37
|
Alila H, Coleman M, Nitta H, French M, Anwer K, Liu Q, Meyer T, Wang J, Mumper R, Oubari D, Long S, Nordstrom J, Rolland A. Expression of biologically active human insulin-like growth factor-I following intramuscular injection of a formulated plasmid in rats. Hum Gene Ther 1997; 8:1785-95. [PMID: 9358028 DOI: 10.1089/hum.1997.8.15-1785] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Recent evidence has shown that insulin-like growth factor-I (IGF-I) plays an important role in the development, maintenance, and regeneration of peripheral nerves and skeletal muscle. IGF-I offers the potential to treat neuromuscular diseases in humans. We have developed a nonviral gene therapy method to express and produce localized and sustained therapeutic levels of IGF-I within target muscles by intramuscular injection of formulated plasmids. The purpose of the present study was to demonstrate that intramuscular injection of a plasmid encoding human IGF-I (hIGF-I) and engineered to restrict expression to skeletal muscle produces sustained local concentrations of biologically active hIGF-I. Normal rats received a single intramuscular injection of plasmids formulated as a complex with polyvinylpyrrolidone (PVP). Results show that hIGF-I mRNA and hIGF-I protein were detectable in the injected muscles for the duration of the study (28 days), whereas the hIGF-I protein was not detected in blood. Biological activity of hIGF-I was determined by immunodetection of a nerve-specific growth-associated protein, GAP-43, an indicator of motor neuron sprouting. Placement of human growth hormone (hGH) 3' untranslated region enhanced GAP-43 staining, probably due to improved secretion of hIGF-I. Enhanced immunoreactivity of GAP-43 was observed in muscles injected with the formulated hIGF-I plasmid when compared to controls. These results demonstrate that intramuscular injection of hIGF-I plasmid formulated as a complex with PVP produces a localized and sustained level of biologically active hIGF-I.
Collapse
Affiliation(s)
- H Alila
- GeneMedicine, Inc. The Woodlands, TX 77381-4248, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Kuo NT, Norman JT, Wilson PD. Acidic FGF regulation of hyperproliferation of fibroblasts in human autosomal dominant polycystic kidney disease. BIOCHEMICAL AND MOLECULAR MEDICINE 1997; 61:178-91. [PMID: 9259983 DOI: 10.1006/bmme.1997.2583] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is characterized by cystic tubule enlargement and expansion of the interstitium associated with fibrosis. Our previous studies have analyzed the increased proliferation of cystic epithelial cells and this study examines the basis of increased proliferation of interstitial fibroblasts associated with ADPKD disease progression. ADPKD fibroblasts show phenotypic alterations in vitro, have acquired the capacity to grow in soft agar, and show an increased mitogenic response to a variety of growth factors particularly acidic FGF (aFGF). ELISA, Western immunoblot analysis, and immunocytochemistry showed increased aFGF content in ADPKD tissues and fibroblasts in culture, and aFGF was secreted into the extracellular matrix and conditioned medium, respectively. No alterations in aFGF receptor number were found, but Scatchard analysis of 125I-aFGF binding suggested an increased affinity of binding to the low affinity receptor, and covalent cross-linking analysis suggested the presence of novel putative receptors (120 kDa) in ADPKD fibroblasts. Signaling abnormalities were found, since aFGF incubation resulted in the tyrosine phosphorylation of additional substrates, more rapidly and for a more sustained duration in ADPKD fibroblasts than in normal fibroblasts. These findings suggest an important role for acidic FGF in the hyperproliferation of interstitial fibroblasts associated with disease progression in human ADPKD.
Collapse
Affiliation(s)
- N T Kuo
- Department of Physiology, UMDNJ-RWJ (formerly Rutgers) Medical School, Piscataway 08854, USA
| | | | | |
Collapse
|
39
|
Kondili K, Tsolas O, Papamarcaki T. Selective interaction between parathymosin and histone H1. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 242:67-74. [PMID: 8954154 DOI: 10.1111/j.1432-1033.1996.0067r.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We have studied the molecular associations of parathymosin, an acidic polypeptide with a wide tissue distribution, by means of three approaches; ligand blotting; native electrophoresis; and immunoprecipitation. We report here that parathymosin binds specifically to the linker histone H1. This binding is enhanced by Zn2+ and is dependent on the concentration of parathymosin. Poly(glutamic acid) is able to compete fully with parathymosin for binding to histone H1, suggesting that this interaction is mediated by the acidic domain of the protein. Moreover, we demonstrate that parathymosin interacts with the globular domain of histone H1 under native conditions. Based on these data, we postulate that parathymosin may belong to a group of nuclear acidic proteins that affect histone H1 function.
Collapse
Affiliation(s)
- K Kondili
- Laboratory of Biological Chemistry, University of Ioannina, Medical School, Greece
| | | | | |
Collapse
|
40
|
Marcellino LH, Neshich G, Grossi de Sá MF, Krebbers E, Gander ES. Modified 2S albumins with improved tryptophan content are correctly expressed in transgenic tobacco plants. FEBS Lett 1996; 385:154-8. [PMID: 8647241 DOI: 10.1016/0014-5793(96)00375-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Brazil nut 2S albumins lack the essential amino acid tryptophan. In order to improve the protein's nutritional value and create a basis for structural investigations, three separate modified Brazil nut 2S albumin genes were constructed. The first mutant contains five consecutive tryptophan codons, while the other two modified genes encode proteins carrying single tryptophan residues at sites that will allow confirmation of the predicted protein structure through fluorescence quenching techniques. The modified genes, under the regulation of the CaMV 35S promoter, were introduced into Nicotiana tabacum. All three modified genes were correctly transcribed and the 2S albumin accumulated in the seeds of transgenic plants.
Collapse
|
41
|
|
42
|
Saalbach I, Pickardt T, Machemehl F, Saalbach G, Schieder O, Müntz K. A chimeric gene encoding the methionine-rich 2S albumin of the Brazil nut (Bertholletia excelsa H.B.K.) is stably expressed and inherited in transgenic grain legumes. MOLECULAR & GENERAL GENETICS : MGG 1994; 242:226-36. [PMID: 8159174 DOI: 10.1007/bf00391017] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The coding region of the 2S albumin gene of Brazil nut (Bertholletia excelsa H.B.K.) was completely synthesized, placed under control of the cauliflower mosaic virus (CaMV) 35S promoter and inserted into the binary vector plasmid pGSGLUC1, thus giving rise to pGSGLUC1-2S. This was used for transformation of tobacco (Nicotiana tabacum L. cv. Petit Havanna) and of the grain legume Vicia narbonensis L., mediated by the supervirulent Agrobacterium tumefaciens strain EHA 101. Putative transformants were selected by screening for neomycin phosphotransferase (NPT II) and beta-glucuronidase (GUS) activities. Transgenic plants were grown until flowering and fruiting occurred. The presence of the foreign gene was confirmed by Southern analysis. GUS activity was found in all organs of the regenerated transgenic tobacco and legume plants, including the seeds. In the legume, the highest expression levels of the CaMV 35S promoter-controlled 2S albumin gene were observed in leaves and roots. 2S albumin was localized in the vacuoles of leaf mesophyll cells of transgenic tobacco. The Brazil nut protein was present in the 2S fraction after gel filtration chromatography of the legume seed proteins and could be clearly identified by immunoblotting. Analysis of seeds from the R2 progenies of the legume and of transgenic tobacco plants revealed Mendelian inheritance of the foreign gene. Agrobacterium rhizogenes strain RifR 15834 harbouring the binary vector pGSGLUC1-2S was also used to transform Pisum sativum L. and Vicia faba L. Hairy roots expressed the 2S albumin-specific gene. Several shoots were raised but they never completely rooted and no fertile plants were obtained from these transformants.
Collapse
Affiliation(s)
- I Saalbach
- Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany
| | | | | | | | | | | |
Collapse
|
43
|
Lauritzen E, Másson M, Rubin I, Bjerrum OJ, Holm A. Peptide dot immunoassay and immunoblotting: electroblotting from aluminum thin-layer chromatography plates and isoelectric focusing gels to activated nitrocellulose. Electrophoresis 1993; 14:852-9. [PMID: 8223393 DOI: 10.1002/elps.11501401136] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Nitrocellulose membrane was preactivated with divinyl sulfone, and a spacer of 1,6-diaminohexane was coupled to the membrane which was functionalized by glutaraldehyde, leaving a reactive carbonyl group. The peptides were coupled to the carbonyl by the side chain and terminal amino groups. The octapeptide angiotensin II (sequence: DRVYIHPF) and peptide analogs containing 6-10 amino acid residues were dotted directly onto the matrix at 45 degrees C for 15 min and detected by specific antisera, which were raised in rabbits against angiotensin I and II, respectively. They were visualized by peroxidase-coupled anti-rabbit IgG antibodies. The detection limit for synthetic angiotensin II was 500 fg per cm2 (= 500 amol per cm2) and for the decapeptide angiotensin I (sequence: DRVYIHPFHL) it was 500 pg per cm2 (= 400 fmol per cm2). Separation of synthetic angiotensin analogs by high performance thin-layer chromatography on silica coated aluminum plates was followed by electroblotting onto activated nitrocellulose and detection with specific antibodies, showing a sensitivity of 100 fg and 1 pg for angiotensin II and angiotensin I, respectively. Isoelectric focusing in agarose using Ampholine carrier ampholytes and immunoblotting with specific antisera displayed a lower sensitivity for angiotensin II and angiotensin I of 2 ng and 20 ng, respectively. The isoelectric focusing and immunoblotting technique was applied for separation of angiotensin I and II and related peptides in serum, where synthetic angiotensin I was degraded in the presence of 1 mM phenylmethylsulfonyl fluoride and 10 mM ethylenediaminetetraacetic acid.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- E Lauritzen
- Department of Virology, Statens Seruminstitute, Copenhagen, Denmark
| | | | | | | | | |
Collapse
|
44
|
Kumari SS, Skinner DM. Proteins Of crustacean exoskeleton II: Immunological evidence for their relatedness to cuticular proteins of two insects. ACTA ACUST UNITED AC 1993. [DOI: 10.1002/jez.1402650302] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
45
|
Abstract
Nucleotide sequence analysis of potato virus X (PVX) genomic RNA predicts five open reading frames (ORFs). Previous analysis of total RNAs from PVX-infected leaf tissue suggested that six subgenomic RNAs are synthesized during infection. However, the proteins encoded by the genomic RNA, the subgenomic RNAs, or the predicted ORFs have not been identified in vivo. To characterize the coding properties of the viral RNA, particularly to determine whether the five predicted ORFs function in vivo, total protein extracts prepared from PVX-infected leaf tissue were analyzed by using antibodies raised against virus-specific synthetic peptides and against the virus capsid protein. Dot blot analyses showed that these antibodies reacted to PVX-infected extracts, indicating in vivo expression of the five predicted ORFs. In addition, Western blot (immunoblot) analysis of the extracts showed that ORF 1, 2, 3, and 4 peptide antisera and coat protein antiserum detect predominantly a single protein.
Collapse
Affiliation(s)
- M Price
- Department of Biochemistry, Louisiana State University, Baton Rouge 70803
| |
Collapse
|
46
|
Kerlin RL, Allingham PG. Acquired immune response of cattle exposed to buffalo fly (Haematobia irritans exigua). Vet Parasitol 1992; 43:115-29. [PMID: 1496794 DOI: 10.1016/0304-4017(92)90054-d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Naturally acquired immunity to buffalo fly (Haematobia irritans exigua) infestation was examined in cattle. Animals exposed to flies had serum antibodies to buffalo fly antigens at levels that correlated with the intensity of exposure. Two weeks of intense exposure to buffalo fly induced an increase in peripheral blood eosinophil numbers and a concomitant rise in serum antibody levels in exposed animals. Antigens specific for antibody induced by natural exposure were identified using antisera from exposed cattle to probe Western blots of whole fly homogenate separated using SDS-PAGE. Similar immunoreactive bands were found with buffalo fly saliva. Immunoreactive proteins were partially purified from whole fly homogenates by anion-exchange chromatography. Fractions eluted from columns were screened using Western blots probed with serum from exposed animals. Exposed animals showed immediate hypersensitivity to partially purified antigens and to buffalo fly saliva. Flies which fed on exposed animals with high serum levels of antibody to fly antigens did not show greater mortality than flies fed on unexposed animals.
Collapse
Affiliation(s)
- R L Kerlin
- CSIRO Division of Tropical Animal Production, Long Pocket Laboratories, Brisbane, Qld., Australia
| | | |
Collapse
|
47
|
Bürgisser P, Frei PC. Characterization of antibodies reacting with HIV gag proteins occasionally found in the serum of non-infected subjects. Clin Exp Immunol 1991; 85:219-23. [PMID: 1713811 PMCID: PMC1535745 DOI: 10.1111/j.1365-2249.1991.tb05708.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The use of serological tests for the diagnosis of HIV infection has revealed that some non-infected persons have antibodies that react with HIV-1 gag proteins. Here, the sera of three non-infected subjects reacting with p17 and 11 non-infected subjects reacting with p24 were investigated, using an enzyme immunoassay (EIA) with six recombinant gag antigens and Western blot analysis of proteolytic peptides of two of these gag antigens. The results indicate that whereas all p17-reactive sera could react with an unique epitope, individual p24-reactive sera recognize different epitopes. Investigations by EIA also demonstrated the role of sequences located far from the epitopes in making these epitopes accessible to the antibodies or in providing them with an antigenic conformation. In addition to the 14 subjects mentioned above, another subject was shown to have antibodies reacting with the p9 (NC) gag protein. Several proteins are known as having homology with HIV-1 gag proteins. Their possible role in eliciting cross-reactive antibodies is discussed.
Collapse
Affiliation(s)
- P Bürgisser
- Division of Immunology and Allergy, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | | |
Collapse
|
48
|
Cohen WM, Wu HF, Featherstone GL, Jenzano JW, Lundblad RL. Linkage between blood coagulation and inflammation: stimulation of neutrophil tissue kallikrein by thrombin. Biochem Biophys Res Commun 1991; 176:315-20. [PMID: 2018525 DOI: 10.1016/0006-291x(91)90926-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
There has been major interest in the potential interaction between blood coagulation and inflammation. Most of the effort has focused on cellular interactions involving platelets and polymorphonuclear leukocytes (PMNS). The recent discovery of tissue kallikrein(TK) activity in PMNs prompted the study of the possible role of thrombin(IIa) in this process. Human PMNs were isolated by density gradient centrifugation. Human IIa was compared with fMLP with respect to chemotaxis and enzyme release. Results from the challenges by IIa and fMLP were compared to a NaCl control using Student's paired t-test. IIa was a potent chemotactic agent for PMNs (p less than or equal to 0.0121) and stimulated the release of TK (p less than or equal to 0.0001) as determined by hydrolysis of S-2266. FMLP significantly stimulated PMN chemotaxis (p less than or equal to 0.0028) but had no effect on TK release. Release of TK was confirmed by Western Blot analysis and 35S-methionine incorporation into a 35 KD protein after IIa challenge. These results demonstrate that IIa is chemotactic for PMNs and can cause release of tissue kallikrein demonstrating a direct role for blood coagulation in the regulation of the inflammatory response.
Collapse
Affiliation(s)
- W M Cohen
- Department of Periodontics, School of Dentistry, University of North Carolina, Chapel Hill 27599-7450
| | | | | | | | | |
Collapse
|
49
|
Evidence that type 1 plasminogen activator inhibitor binds to the somatomedin B domain of vitronectin. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)49921-8] [Citation(s) in RCA: 116] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
50
|
Froehlich JE, Poorman R, Reardon E, Barnum SR, Jaworski JG. Purification and characterization of acyl carrier protein from two cyanobacteria species. EUROPEAN JOURNAL OF BIOCHEMISTRY 1990; 193:817-25. [PMID: 2123456 DOI: 10.1111/j.1432-1033.1990.tb19405.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The acyl carrier protein (ACP), an essential protein cofactor for fatty acid synthesis, has been isolated from two cyanobacteria: the filamentous, heterocystous, Anabaena variabilis (ATCC 29211) and the unicellular Synechocystis 6803 (ATCC 27184). Both ACPs have been purified to homogeneity utilizing a three-column procedure. Synechocystis 6803 ACP was purified 1800-fold with 67% yield, while A. variabilis ACP was purified 1040-fold with 50% yield. Yields of 13.0 micrograms ACP/g Synechocystis 6803 and 9.0 micrograms ACP/g A. variabilis were achieved. Amino acid analysis indicated that these ACPs were highly charged acidic proteins similar to other known ACPs. Sequence analysis revealed that both cyanobacterial ACPs were highly conserved with both spinach and Escherichia coli ACP at the phosphopantetheine prosthetic group region. Examining the probability of alpha-helix and beta-turn regions in various ACPs, showed that cyanobacterial ACPs were more closely related to E. coli ACP than spinach ACP I. Immunoblot analysis and a competitive binding assay for ACP illustrated that both ACPs bound poorly to spinach ACP I antibody. SDS/PAGE and native PAGE of Synechocystis 6803 ACP and A. variabilis ACP showed that cyanobacteria ACPs co-migrated with E. coli ACP and had relative molecular masses of 18,100 and 17,900 respectively. Both native and urea gel analysis of acyl-ACP products from fatty acid synthase reactions demonstrated that bacterial ACPs and plant ACP gave essentially the same metabolic products when assayed using either bacterial or plant fatty acid synthase. A. variabilis and Synechocystis 6803 ACP could be acylated using E. coli acyl ACP synthetase.
Collapse
Affiliation(s)
- J E Froehlich
- Department of Chemistry, Miami University, Oxford, OH 45056
| | | | | | | | | |
Collapse
|