Molecular Biology and Genetics / Moleküler Biyoloji ve Genetik

Permanent URI for this collectionhttps://hdl.handle.net/11147/9

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  • Article
    Citation - WoS: 3
    Citation - Scopus: 3
    A Subtractive Proteomics Approach for the Identification of Immunodominant Acinetobacter Baumannii Vaccine Candidate Proteins
    (Frontiers Media S.A., 2022) Acar, Mustafa Burak; Ayaz Güner, Şerife; Güner, Hüseyin; Dinç, Gökçen; Ulu Kılıç, Ayşegül; Doğanay, Mehmet; Özcan, Servet
    Background: Acinetobacter baumannii is one of the most life-threatening multidrug-resistant pathogens worldwide. Currently, 50%–70% of clinical isolates of A. baumannii are extensively drug-resistant, and available antibiotic options against A. baumannii infections are limited. There is still a need to discover specific de facto bacterial antigenic proteins that could be effective vaccine candidates in human infection. With the growth of research in recent years, several candidate molecules have been identified for vaccine development. So far, no public health authorities have approved vaccines against A. baumannii. Methods: This study aimed to identify immunodominant vaccine candidate proteins that can be immunoprecipitated specifically with patients’ IgGs, relying on the hypothesis that the infected person’s IgGs can capture immunodominant bacterial proteins. Herein, the outer-membrane and secreted proteins of sensitive and drug-resistant A. baumannii were captured using IgGs obtained from patient and healthy control sera and identified by Liquid Chromatography- Tandem Mass Spectrometry (LC-MS/MS) analysis. Results: Using the subtractive proteomic approach, we determined 34 unique proteins captured only in drug-resistant A. baumannii strain via patient sera. After extensively evaluating the predicted epitope regions, solubility, transverse membrane characteristics, and structural properties, we selected several notable vaccine candidates. Conclusion: We identified vaccine candidate proteins that triggered a de facto response of the human immune system against the antibiotic-resistant A. baumannii. Precipitation of bacterial proteins via patient immunoglobulins was a novel approach to identifying the proteins that could trigger a response in the patient immune system.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Protocol for Cell Surface Biotinylation of Magnetic Labeled and Captured Human Peripheral Blood Mononuclear Cells
    (Elsevier, 2022) Ayaz Güner, Şerife; Acar, Mustafa Burak; Boyvat, Dudu; Güner, Hüseyin; Bozalan, Habibe; Güzel, Melis; Yıldır, Selin Kübra; Altınsoy, Nilay; Fındık, Fatma; Karakükçü, Musa; Özcan, Servet
    Analysis of the surfaceome of a blood cell subset requires cell sorting, followed by surface protein enrichment. Here, we present a protocol combining magnetically activated cell sorting (MACS) and surface biotinylation of the target cell subset from human peripheral blood mononuclear cells (PBMCs). We describe the steps for isolating target cells and their in-column surface biotinylation, followed by isolation and mass spectrometry analysis of biotinylated proteins. The protocol enables in-column surface biotinylation of specific cell subsets with minimal membrane disruption.
  • Article
    Comparative Proteome Profiles of Methicillin-Resistant Staphylococcus Aureus in Response To Vanillic Acid and 2-Hydroxycinnamic Acid
    (Bentham Science Publishers, 2021) Keman, Deniz; Soyer, Ferda
    Background: The ability of Staphylococcus aureus to cause severe infections and the difficulty of the treatments due to the multiple antibiotic resistance make this bacterium a lifethreatening human pathogen. This situation necessitates the exploration of novel antimicrobial compounds with known targets on bacteria. Phenolic acids naturally produced in plants as secondary metabolites are good candidates for being alternative antimicrobials for antibiotic-resistant bacteria. Objective: Investigation of protein profile of Methicillin-Resistant S. Aureus (MRSA) in the presence of subinhibitory concentrations of phenolic acids. Methods: MRSA was subjected to subinhibitory concentrations of Vanillic Acid (VA) and 2-Hydroxycinnamic Acid (2-HCA), separately, and the proteomic analyses were carried out by using liquid chromatography coupled to mass spectrometry. Results: Both phenolic acids elicited identification of differently expressed proteins that have roles in DNA replication, repair, RNA processing and transcription, protein synthesis, maintenance of cell homeostasis, several metabolic reactions in energy, carbohydrate and lipid metabolisms and also proteins related with the virulence and the pathogenicity of MRSA when compared with the control group. The numbers of the proteins identified were 444, 375, and 426 for control, VA-treated MRSA, and 2-HCA-treated MRSA, respectively, from which 256 were shared. While VA treatment resulted in 149 unidentified MRSA proteins produced in control, 2-HCA treatment resulted in 126 unidentified proteins. Data are available via ProteomeXchange with identifier PXD016922. Conclusion: The results obtained from this study might indicate the potential targets on bacteria and the effective use of phenolic acids in the battle with antibiotic-resistant pathogens.
  • Letter
    Citation - Scopus: 9
    A Call for Benchmark Data in Mass Spectrometry-Based Proteomics
    (Proteomass Scientific Society, 2012) Allmer, Jens
    Proteomics is a quickly developing field. New and better mass spectrometers, the platform of choice in proteomics, are being introduced frequently. New algorithms for the analysis of mass spectrometric data and assignment of amino acid sequence to tandem mass spectra are also presented on a frequent basis. Unfortunately, the best application area for these algorithms cannot be established at the moment. Furthermore, even the accuracy of the algorithms and their relative performance cannot be established. This is due to the lack of proper benchmark data. This letter first introduces the field of mass spectrometry-based proteomics and then defines the expectations of a well-designed benchmark dataset. Thereafter, the current situation is compared to this ideal. A call for the creation of a proper benchmark dataset is then placed and it is explained how measurement should be performed. Finally, the benefits for the research community are highlighted. © 2012, Proteomass Scientific Society. All rights reserved.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 7
    The Importance of Protein Profiling in the Diagnosis and Treatment of Hematologic Malignancies
    (Galenos Yayıncılık, 2011) Şanlı Mohamed, Gülşah; Turan, Taylan; Ekiz, Hüseyin Atakan; Baran, Yusuf
    Proteins are important targets in cancer research because malignancy is associated with defects in cell protein machinery. Protein profiling is an emerging independent subspecialty of proteomics that is rapidly expanding and providing unprecedented insight into biological events. Quantitative assessment of protein levels in hematologic malignancies seeks a comprehensive understanding of leukemiaassociated protein patterns for use in aiding diagnosis, follow-up treatment, and the prediction of clinical outcomes. Many recently developed high-throughput proteomic methods can be applied to protein profiling. Herein the importance of protein profiling, its exploitation in leukemia research, and its clinical usefulness in the treatment and diagnosis of various cancer types, and techniques for determining changes in protein profiling are reviewed.
  • Article
    Citation - WoS: 11
    Citation - Scopus: 14
    Proteomic Changes During Boron Tolerance in Barley (hordeum Vulgare) and the Role of Vacuolar Proton-Translocating Atpase Subunit E
    (Türkiye Klinikleri Journal of Medical Sciences, 2011) Atik, Ahmet Emin; Bozdağ, Gönensin Ozan; Akıncı, Ersin; Kaya, Alaattin; Koç, Ahmet; Yalçın, Talat; Karakaya, Hüseyin Çağlar
    Boron is an essential micronutrient for plants and animals; however, it can be toxic when present at high concentrations. The purpose of this study was to understand the mechanisms of boron tolerance in the Turkish barley (Hordeum vulgare) Anadolu cultivar. For this purpose, 2-dimensional electrophoresis (2-DE) was used to screen differentially expressed proteins for both control and boron-stressed Anadolu barley genotypes. Seven proteins were revealed by 2-DE: 1) ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCo large chain), 2) TLP5, a thaumatin-like protein, 3) PR5, a basic pathogenesis-related protein, 4) a RNase S-like protein, 5) a PSI type III chlorophyll a/b-binding protein, 6) a light-harvesting complex I LHC I, and 7) the vacuolar proton-translocating ATPase subunit E protein. These were found to be upregulated in response to boron treatment. Even though the protein encoded by the V-ATPase subunit E gene was overexpressed, its transcript level was downregulated by boron treatment. Heterologous expression of the barley V-ATPase subunit E gene in yeast provided boron resistance to yeast cells. These results indicated that the V-ATPase subunit E gene was functional and conferred tolerance to toxic boron levels in yeast and might play a role in the overall boron tolerance of barley. © TÜBITAK.
  • Conference Object
    Citation - Scopus: 1
    De Novo Markup Language, a Standard To Represent De Novo Sequencing Results From Ms/Ms Data
    (Institute of Electrical and Electronics Engineers Inc., 2012) Takan, Savaş; Allmer, Jens
    Proteomics is the study of the proteins that can be derived from a genome. For the identification and sequencing of proteins, mass spectrometry has become the tool of choice. Within mass spectrometry-based proteomics, proteins can be identified or sequenced by either database search or de novo sequencing. Both methods have certain advantages and drawbacks but in the long run we envision de novo sequencing to become the predominant tool. Currently, de novo sequencing results are stored in arbitrary file formats, depending on the developers of the algorithms. We identified this as a large and unnecessary obstacle while integrating results from multiple de novo sequencing algorithms. Therefore, we designed a standard file format for the representation of de novo sequencing results. We further developed an application programming interface since we identified the lack of proper APIs as another obstacle, introducing a needlessly high learning curve for developers. © 2012 IEEE.
  • Article
    Citation - WoS: 91
    Citation - Scopus: 106
    Algorithms for the De Novo Sequencing of Peptides From Tandem Mass Spectra
    (Taylor & Francis, 2011) Allmer, Jens
    Proteomics is the study of proteins, their time- and location-dependent expression profiles, as well as their modifications and interactions. Mass spectrometry is useful to investigate many of the questions asked in proteomics. Database search methods are typically employed to identify proteins from complex mixtures. However, databases are not often available or, despite their availability, some sequences are not readily found therein. To overcome this problem, de novo sequencing can be used to directly assign a peptide sequence to a tandem mass spectrometry spectrum. Many algorithms have been proposed for de novo sequencing and a selection of them are detailed in this article. Although a standard accuracy measure has not been agreed upon in the field, relative algorithm performance is discussed. The current state of the de novo sequencing is assessed thereafter and, finally, examples are used to construct possible future perspectives of the field. © 2011 Expert Reviews Ltd.
  • Article
    Citation - WoS: 20
    Citation - Scopus: 20
    Genome-Wide Identification of Genes That Play a Role in Boron Stress Response in Yeast
    (Elsevier Ltd., 2011) Uluışık, İrem; Kaya, Alaattin; Ünlü, Ercan Selçuk; Avşar, Kadir; Karakaya, Hüseyin Çağlar; Yalçın, Talat; Koç, Ahmet
    Boron is an essential micronutrient for plants and it is either necessary or beneficial for animals. Studies identified only few genes related to boron metabolism thus far and details of how boron is imported into cells and used in cell metabolism are largely unknown. In order to identify genes that play roles in boron metabolism, we screened the entire set of yeast haploid deletion mutants and identified 6 mutants that were resistant to toxic levels of boron, and 21 mutants that were highly sensitive to boron treatment. Furthermore, we performed a proteomic approach to identify additional proteins that are significantly up-regulated by boron treatment. Our results revealed many genes and pathways related to boron stress response and suggest a possible link between boron toxicity and translational control.