Protein-glutamine Gamma-glutamyltransferase Research Articles

A guide to selecting high-performing antibodies for Protein-glutamine gamma-glutamyltransferase 2 (TGM2) for use in western blot, immunoprecipitation and immunofluorescence

Protein-glutamine gamma-glutamyltransferase 2 (TGM2) is a Ca2+ dependent enzyme that catalyzes transglutaminase cross-linking modifications. TGM2 is involved in various diseases, either in a protective or contributory manner, making it a crucial protein to study and determine its therapeutic potential. Identifying high-performing TGM2 antibodies would facilitate these investigations. Here we have characterized seventeen TGM2 commercial antibodies for western blot and sixteen for immunoprecipitation, and immunofluorescence. The implemented standardized experimental protocol is based on comparing read-outs in knockout cell lines against their isogenic parental controls. This study is part of a larger, collaborative initiative seeking to address antibody reproducibility issues by characterizing commercially available antibodies for human proteins and publishing the results openly as a resource for the scientific community. While the use of antibodies and protocols vary between laboratories, we encourage readers to use this report as a guide to select the most appropriate antibodies for their specific needs.

Effect of empagliflozin on circulating proteomics in heart failure: mechanistic insights into the EMPEROR programme.

Sodium-glucose co-transporter 2 (SGLT2) inhibitors improve cardiovascular outcomes in diverse patient populations, but their mechanism of action requires further study. The aim is to explore the effect of empagliflozin on the circulating levels of intracellular proteins in patients with heart failure, using large-scale proteomics. Over 1250 circulating proteins were measured at baseline, Week 12, and Week 52 in 1134 patients from EMPEROR-Reduced and EMPEROR-Preserved, using the Olink® Explore 1536 platform. Statistical and bioinformatical analyses identified differentially expressed proteins (empagliflozin vs. placebo), which were then linked to demonstrated biological actions in the heart and kidneys. At Week 12, 32 of 1283 proteins fulfilled our threshold for being differentially expressed, i.e. their levels were changed by ≥10% with a false discovery rate <1% (empagliflozin vs. placebo). Among these, nine proteins demonstrated the largest treatment effect of empagliflozin: insulin-like growth factor-binding protein 1, transferrin receptor protein 1, carbonic anhydrase 2, erythropoietin, protein-glutamine gamma-glutamyltransferase 2, thymosin beta-10, U-type mitochondrial creatine kinase, insulin-like growth factor-binding protein 4, and adipocyte fatty acid-binding protein 4. The changes of the proteins from baseline to Week 52 were generally concordant with the changes from the baseline to Week 12, except empagliflozin reduced levels of kidney injury molecule-1 by ≥10% at Week 52, but not at Week 12. The most common biological action of differentially expressed proteins appeared to be the promotion of autophagic flux in the heart, kidney or endothelium, a feature of 6 proteins. Other effects of differentially expressed proteins on the heart included the reduction of oxidative stress, inhibition of inflammation and fibrosis, and the enhancement of mitochondrial health and energy, repair, and regenerative capacity. The actions of differentially expressed proteins in the kidney involved promotion of autophagy, integrity and regeneration, suppression of renal inflammation and fibrosis, and modulation of renal tubular sodium reabsorption. Changes in circulating protein levels in patients with heart failure are consistent with the findings of experimental studies that have shown that the effects of SGLT2 inhibitors are likely related to actions on the heart and kidney to promote autophagic flux, nutrient deprivation signalling and transmembrane sodium transport.

Untangling the Extracellular Matrix of Idiopathic Epiretinal Membrane: A Path Winding among Structure, Interactomics and Translational Medicine.

Idiopathic epiretinal membranes (iERMs) are fibrocellular sheets of tissue that develop at the vitreoretinal interface. The iERMs consist of cells and an extracellular matrix (ECM) formed by a complex array of structural proteins and a large number of proteins that regulate cell–matrix interaction, matrix deposition and remodelling. Many components of the ECM tend to produce a layered pattern that can influence the tractional properties of the membranes. We applied a bioinformatics approach on a list of proteins previously identified with an MS-based proteomic analysis on samples of iERM to report the interactome of some key proteins. The performed pathway analysis highlights interactions occurring among ECM molecules, their cell receptors and intra- or extracellular proteins that may play a role in matrix biology in this special context. In particular, integrin β1, cathepsin B, epidermal growth factor receptor, protein-glutamine gamma-glutamyltransferase 2 and prolow-density lipoprotein receptor-related protein 1 are key hubs in the outlined protein–protein cross-talks. A section on the biomarkers that can be found in the vitreous humor of patients affected by iERM and that can modulate matrix deposition is also presented. Finally, translational medicine in iERM treatment has been summed up taking stock of the techniques that have been proposed for pharmacologic vitreolysis.

PD36-09 DIFFERENTIAL EXPRESSION OF SEMINAL PLASMA PROTEINS IN RESPONDERS AND NON-RESPONDERS TO VARICOCELE TREATMENT

You have accessJournal of UrologyCME1 May 2022PD36-09 DIFFERENTIAL EXPRESSION OF SEMINAL PLASMA PROTEINS IN RESPONDERS AND NON-RESPONDERS TO VARICOCELE TREATMENT Timur Bitsoev, Vitaliy Chagovets, Taras Shatylko, Alisa Tokareva, Safar Gamidov, Natalia Starodubtseva, Alina Popova, and Vladimir Frankevich Timur BitsoevTimur Bitsoev More articles by this author , Vitaliy ChagovetsVitaliy Chagovets More articles by this author , Taras ShatylkoTaras Shatylko More articles by this author , Alisa TokarevaAlisa Tokareva More articles by this author , Safar GamidovSafar Gamidov More articles by this author , Natalia StarodubtsevaNatalia Starodubtseva More articles by this author , Alina PopovaAlina Popova More articles by this author , and Vladimir FrankevichVladimir Frankevich More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002594.09AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Despite large amounts of evidence linking varicocele to male infertility, the role of varicocele repair in infertile men is controversial. Even after technically perfect operation not all couples achieve pregnancy or at least have a significant improvement in semen parameters. Probably, there are cases of infertility which share a causal relationship with varicocele, and there are cases when idiopathic infertility co-exists with harmless varicocele. Unfortunately, there is no way to predict response to varicocele treatment among infertile males. Since sperm are transcriptionally inert, the proteome of seminal plasma is relatively stable and may reflect the true extent of deleterious effects of varicocele, such as oxidative stress and hyperthermia. Our goal was to assess whether proteomic signature of seminal plasma may help to distinguish responders and non-responders to varicocele repair. METHODS: We used mass-spectrometry to perform a proteomic analysis of seminal plasma specimens obtained from 10 infertile patients (age: 25–44 years) with bilateral varicocele. All patients underwent routine semen analysis and had at least two altered core parameters out of three (total sperm count, progressive motility, percentage of sperm with normal morphology). Microsurgical bilateral subinguinal varicocelectomy was performed in all patients. Routine semen analysis and proteomic analysis were repeated at follow-up, which was scheduled at 6 months after the surgery. Responders were defined as patients whose spouse became pregnant during follow-up period or whose total motile sperm count increased by at least 50%. Proteomic profiles of responders and non-responders were compared. RESULTS: Five patients were responders to varicocele repair (partners of two of them became pregnant). Proteomic analysis identified 18 proteins with differential expression in responders and non-responders: melanophilin, kallikrein-2, alpha-actinin-4, Kunitz-type protease inhibitor 3, alpha-1-acid glycoprotein 1, CD177 antigen, alpha-1-acid glycoprotein 2, protein-glutamine gamma-glutamyltransferase 4, phosphatidylethanol amine-binding protein 4, acyl-CoA-binding protein, hemoglobin subunit alpha, antileukoproteinase, collagen alpha-1(XVIII) chain, vitronectin, serine protease HTRA1, V-type proton ATPase catalytic subunit A, endoplasmic reticulum resident protein 44, NADP-dependent malic enzyme. CONCLUSIONS: If validated, semen proteomics may become a useful tool to predict response to varicocele repair and avoid unnecessary surgery. Source of Funding: N/A © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e636 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Timur Bitsoev More articles by this author Vitaliy Chagovets More articles by this author Taras Shatylko More articles by this author Alisa Tokareva More articles by this author Safar Gamidov More articles by this author Natalia Starodubtseva More articles by this author Alina Popova More articles by this author Vladimir Frankevich More articles by this author Expand All Advertisement PDF DownloadLoading ...

Proteome and secretome analysis of pancreatic cancer cells.

Pancreatic cancer is a lethal malignancy and no screening biomarker or targeted therapy is currently available. Here, we performed a shotgun proteomic label-free quantification (LFQ) to define protein changes in the cellular proteome and secretome of four pancreatic cancer cell lines (PANC1, Paca44, Paca2, and BXPC3) versus normal human pancreatic ductal epithelial cells (HPDE). In the cellular proteome and secretome, 149 and 43 proteins were dysregulated in the most cancer cell lines, respectively. Using Ingenuity Pathway Analysis (IPA), the most dysregulated signaling pathways in pancreatic cancer cells included the activation of epidermal growth factor receptor (EGFR), phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), extracellular regulated kinase (ERK), and the deactivation of type-I interferon (IFN) pathways, which could promote cancer cell progression and decrease antitumor immunity. Parallel reaction monitoring (PRM) mass spectrometry was used to confirm the changes of seven regulated proteins quantified by LFQ: EGFR, growth/differentiation factor 15 (GDF15), protein-glutamine gamma-glutamyltransferase 2 (TGM2), leukemia inhibitory factor (LIF), interferon-induced GTP-binding protein Mx1 (MX1), signal transducer and activator of transcription 1 (STAT1), and serpin B5 (SERPINB5). Together, this proteomic analysis highlights protein changes associated with pancreatic cancer cells that should be further investigated as potential biomarkers or therapeutic targets.

Urine Proteomic Analysis of Differences Between Patients With Hyperthyroidism Before and After Carbimazole Treatment

Abstract Background: Hyperthyroidism, characterised by increased circulating thyroid hormone (TH) levels, alters the body’s metabolic and systemic haemodynamic balance and directly influences renal function However, the underlying mechanisms and metabolic implications of these changes are not well understood. Objective: In the present study we aimed to study the changes occurring in the urinary proteome of patients with hyperthyroidism before and after treatment. The levels of the excreted proteins in the urine were studied using an untargeted 2D DIGE MALDI TOF proteomic approach with network analysis. Methods: The study included 9 age matched patients with mean age 38.6 ± 12.1 years with newly diagnosed hyperthyroidism. The patients were evaluated at baseline and after receiving treatment with carbimazole. Urine samples were obtained from the same patient at baseline (hyperthyroid state) with serum FT4 levels of 35.4 + 9.9 pmol/L and TSH 0.014 + 0.014 mIU/L (mean + SD), and post treatment with anti-thyroid drugs (euthyroid state) with levels of FT4 17.0 + 2.8 pmol/L and TSH 0.6 + 0.5 mIU/L (mean + SD). Results: Alterations in the abundance of urinary proteins, analyzed by Progenesis software, revealed statistically significant differential abundance in a total of 40 spots corresponding to 33 proteins, 26 up and 7 down (≥1.5-fold change, ANOVA, p ≤ 0.05). The proteins identified in the study are known to regulate processes related to cellular metabolism, transport, acute phase response. The urinary proteins upregulated with hyperthyroidism included serotransferrin, transthyretin, serum albumin, ceruloplasmin, α1B glycoprotein, syntenin-1, nesprin, and glutamilnyl peptide cyclotransferase while the 3 notable down regulated proteins were plasma kallikrein, protein glutamine gamma-glutamyl transferase and serpin B3. Bioinformatic analysis using Ingenuity Pathway Analysis (IPA) identified dysregulation of pathways related to cellular compromise, inflammatory response, cellular assembly and organization and identified the involvement of the APP and AKT signaling pathways via their interactions with interleukins as the central nodes. Conclusion: The urine proteomic profiling between the hyperthyroid and euthyroid states demonstrates alteration in the protein levels involved in acute phase response and in maintaining an individual’s haemodynamic state.

Proteomics Profiling of the Urine of Patients with Hyperthyroidism after Anti-Thyroid Treatment.

Hyperthyroidism, which is characterized by increased circulating thyroid hormone levels, alters the body’s metabolic and systemic hemodynamic balance and directly influences renal function. In this study, the urinary proteome of patients with hyperthyroidism was characterized using an untargeted proteomic approach with network analysis. Urine samples were collected from nine age-matched patients before and after carbimazole treatment. Differences in the abundance of urinary proteins between hyperthyroid and euthyroid states were determined using a 2D-DIGE coupled to MALDI-TOF mass spectrometry. Alterations in the abundance of urinary proteins, analyzed via Progenesis software, revealed a statistically significant difference in abundance in a total of 40 spots corresponding to 32 proteins, 25 up and 7 down (≥1.5-fold change, ANOVA, p ≤ 0.05). The proteins identified in the study are known to regulate processes associated with cellular metabolism, transport, and acute phase response. The notable upregulated urinary proteins were serotransferrin, transthyretin, serum albumin, ceruloplasmin, alpha-1B-glycoprotein, syntenin-1, and glutaminyl peptide cyclotransferase, whereas the three notable downregulated proteins were plasma kallikrein, protein glutamine gamma-glutamyl transferase, and serpin B3 (SERPINB3). Bioinformatic analysis using ingenuity pathway analysis (IPA) identified the dysregulation of pathways associated with cellular compromise, inflammatory response, cellular assembly, and organization and identified the involvement of the APP and AKT signaling pathways via their interactions with interleukins as the central nodes.

Proteomic Analysis of the Hemolymph After Metschnikowia bicuspidata Infection in the Chinese Mitten Crab Eriocheir sinensis.

The “milky disease” of the Chinese mitten crab, Eriocheir sinensis, is a highly lethal fungal disease caused by Metschnikowia bicuspidata infection. To elucidate the immune responses of the hemolymph of E. sinensis to M. bicuspidata infection, a comparative analysis of the hemolymph of E. sinensis infected with M. bicuspidata and that treated with phosphate buffered saline was performed using label-free quantitative proteomics. A total of 429 proteins were identified. Using a 1.5-fold change in expression as a physiologically significant benchmark, 62 differentially expressed proteins were identified, of which 38 were significantly upregulated and 24 were significantly downregulated. The upregulated proteins mainly included cytoskeleton-related proteins (myosin regulatory light chain 2, myosin light chain alkali, tubulin α-2 chain, and tubulin β-1 chain), serine protease and serine protease inhibitor (clip domain-containing serine protease, leukocyte elastase inhibitor, serine protein inhibitor 42Dd), catalase, transferrin, and heat shock protein 70. Upregulation of these proteins indicated that phenoloxidase system, phagocytosis and the ROS systems were induced by M. bicuspidata. The downregulated proteins were mainly organ and tissue regeneration proteins (PDGF/VEGF-related factor protein, integrin-linked protein kinase homing pat-4 gene) and hemagglutination-associated proteins (hemolymph clottable protein, hemocyte protein-glutamine gamma-glutamyltransferase). Downregulation of these proteins indicated that M. bicuspidata inhibited hemocyte regeneration and hemolymph agglutination. Fifteen differentially expressed proteins related to immunity were verified using a parallel reaction monitoring method. The expression trend of these proteins was similar to that of the proteome. To the best of our knowledge, this is the first report on the proteome of E. sinensis in response to M. bicuspidata infection. These results not only provide new and important information on the immune response of crustaceans to yeast infection but also provide a basis for further understanding the molecular mechanism of complex host pathogen interactions between crustaceans and fungi.

Growth and health responses to a long-term pH stress in Pacific white shrimp Litopenaeus vannamei

Environmental pH change is a challenge for growth and health of aquatic animals. In this study, the juveniles of Pacific white shrimp Litopenaeus vannamei were exposed to a higher pH 9.5 or a lower pH 6.5 versus a normal pH (pH 8.0) as the control for four weeks. Growth performance, antioxidant capacity, immune functions, and intestinal histological damage and microbiota were evaluated. The weight gain rate was significantly decreased in shrimp at pH 9.5 compared with the control shrimp at pH 8.0. The antioxidant capacities of shrimp as activities of SOD, GSH-Px, GST and MDA contents shown at pH 9.5 or pH 6.5 were significantly reduced relative to the control shrimp. The expressions of immune-related genes, including anti-lipopolysaccharide factor, lysozyme, protein toll, immune deficiency, and hemocyte protein-glutamine gamma-glutamyltransferase, were down-regulated and the intestine tissues were distorted. Histology analysis showed that shrimp gut epithelial cells at pH 6.5 separated from the basement membrane, while epithelial cell necrosis were found in shrimp at pH 9.5. The diversity of intestine microbiota was disturbed with lower Shannon and higher Simpson indices in shrimp at pH 6.5 than the control shrimp, but no differences were found in shrimp at pH 9.5. The intestine barrier functions were weakened as the KEGG analysis shown, where functions for protein or carbohydrate digestion and absorption at pH 6.5, and for antibiotics biosynthesis, including streptomycin, penicillin, cephalosporin, novobiocin, ansamycins and vancomycin, at pH 9.5 in shrimp were significantly decreased. All finding in this study suggest that long-term lower or higher pH stress could adversely affect gut microbiota functions, thus leading to shrimp reduced growth, immunity and antioxidant capacity, and even intestine histology damage.

Multi-omics Biomarker Pipeline Reveals Elevated Levels of Protein-glutamine Gamma-glutamyltransferase 4 in Seminal Plasma of Prostate Cancer Patients

Seminal plasma, because of its proximity to prostate, is a promising fluid for biomarker discovery and noninvasive diagnostics. In this study, we investigated if seminal plasma proteins could increase diagnostic specificity of detecting primary prostate cancer and discriminate between high- and low-grade cancers. To select 147 most promising biomarker candidates, we combined proteins identified through five independent experimental or data mining approaches: tissue transcriptomics, seminal plasma proteomics, cell line secretomics, tissue specificity, and androgen regulation. A rigorous biomarker development pipeline based on selected reaction monitoring assays was designed to evaluate the most promising candidates. As a result, we qualified 76, and verified 19 proteins in seminal plasma of 67 negative biopsy and 152 prostate cancer patients. Verification revealed a prostate-specific, secreted and androgen-regulated protein-glutamine gamma-glutamyltransferase 4 (TGM4), which predicted prostate cancer on biopsy and outperformed age and serum Prostate-Specific Antigen (PSA). A machine-learning approach for data analysis provided improved multi-marker combinations for diagnosis and prognosis. In the independent verification set measured by an in-house immunoassay, TGM4 protein was upregulated 3.7-fold (p = 0.006) and revealed AUC = 0.66 for detecting prostate cancer on biopsy for patients with serum PSA ≥4 ng/ml and age ≥50. Very low levels of TGM4 (120 pg/ml) were detected in blood serum. Collectively, our study demonstrated rigorous evaluation of one of the remaining and not well-explored prostate-specific proteins within the medium-abundance proteome of seminal plasma. Performance of TGM4 warrants its further investigation within the distinct genomic subtypes and evaluation for the inclusion into emerging multi-biomarker panels.

Proteomics reveals a set of highly enriched proteins in epiretinal membrane compared with inner limiting membrane

Few data exist regarding the protein composition of idiopathic epiretinal membrane (iERM). In the present study we compared the proteome of epiretinal membrane of iERM with the proteome of the inner limiting membrane (ILM) of idiopathic macular hole (iMH). Twelve epiretinal membrane samples were obtained from patients with iERM undergoing therapeutic vitrectomy. Twelve ILM samples from patients with iMH were used as controls. Proteomic analysis was conducted with discovery-based label-free quantitative nano-liquid chromatography - tandem mass spectrometry (LFQ nLC-MS/MS). Verification of results was performed with targeted MS using selected reaction monitoring on a different set of samples. Discovery data were searched against the Uniprot Homo sapiens protein database using MaxQuant Software. Identified proteins were filtered with Perseus software. Bioinformatic analysis of the differences in protein expression between epiretinal membrane from iERM and ILM from iMH was performed using STRING. A total of 2,183 different proteins were identified. 357 proteins were found to be present in all samples. The protein profile of iERM was highly different from iMH with 62 proteins found at significantly higher levels in iERM. The proteins upregulated more than 10-fold in iERM were: fibrillin-1, tenascin, prolargin, biglycan, opticin, collagen alpha-1(II) chain, protein-glutamine gamma-glutamyltransferase 2, fibronectin, filamin-A, collagen alpha-2(IX) chain, spectrin alpha chain, transforming growth factor beta induced protein ig–h3, dihydropyrimidinase - related protein 3, endoplasmin and glutamate dehydrogenase 1. Proteins with high level in iERM consisted of proteins that especially localized to the actin cytoskeleton, the extracellular matrix and the mitochondrion. Analysis of all proteins indicated that the disease process in iERM at least in part can be characterized as skin formation with perturbation of nucleotide metabolism. Our study identified proteins that have not earlier been associated with iERM. Fifteen proteins are found at very high concentration, 10-fold or more, and amongst these four proteins, fibrillin-1, tenascin, prolargin and biglycan were found at more than a 100-fold higher content compared to ILM of iMH. These proteins may be potential therapeutic targets. Data are available via ProteomeXchange with identifier PXD014286.

Quantitative proteomic profiling of immune responses to Ichthyophthirius multifiliis in common carp skin mucus

Ichthyophthirius multifiliis, a ciliated protozoan parasite, causes ichthyophthiriasis and leads to considerable economic losses to the aquaculture industry. Understanding the fish immune response and host-parasite interactions could support developing novel strategies for better disease management and control. Fish skin mucus is the first line of defence against infections through the epidermis. Yet, the common carp, Cyprinus carpio, protein-based defence strategies against infection with I. multifiliis at this barrier remain elusive. The skin mucus proteome of common carp was investigated at 1 day and 9 days post-exposure with I. multifiliis. Using nano-LC ESI MS/MS and statistical analysis, the abundance of 19 immune related and signal transduction proteins was found to be differentially regulated in skin mucus of common carp in response to I. multifiliis. The analysis revealed increased abundance values of epithelial chloride channel protein, galactose-specific lectin nattection, high choriolytic enzyme 1 (nephrosin), lysozyme C, granulin and protein-glutamine gamma-glutamyltransferase 2 in I. multifiliis-exposed carp skin mucus. Multiple lectins and a diverse array of distinct serpins with protease inhibitor activity were identified likely implicated in lectin pathway activation and regulation of proteolysis, indicating that these proteins contribute to the carp innate immune system and the protective properties of skin mucus. The results obtained from this proteomic analysis enables a better understanding of fish host response to parasitic infection and gives insights into the key role skin mucus plays in protecting fish against deleterious effects of I. multifiliis.

Effect of enzymatic transglutaminase treatment on textural and sensory properties of low-fat UF-Feta cheese incorporated with whey proteins using response surface optimization.

شواهد علمی نشان داده است که مصرف چربی ارتباط مستقیمی با بیماری های مختلفی از جمله چاقی، دیابت، سفت شدن دیواره رگ ها و فشار خون دارد. به همین دلیل طی سال های اخیر تقاضا برای محصولات کم‌چرب افزایش چشمگیری پیدا کرده است. پنیر به‌عنوان یک فراورده لبنی با ارزش نقش پررنگی در رژیم غذایی جامعه دارد. با این حال این فراورده حاوی مقادیر بالایی از چربی می باشد که سبب ایجاد نگرانی های از جانب مصرف‌کنندگان شده است. در این پژوهش از روش سطح پاسخ به‌منظور مطالعه اثر آنزیم ترانس گلوتامیناز (2-0 واحد به ازای هرگرم پروتئین)، محلول کنسانتره پروتئینی آب پنیر یا WPC (16-0 درصد) و سطوح چربی (10-0 درصد) بر خواص کیفی و بهینه‌سازی فرمولاسیون پنیر فراپالایش کم‌چرب استفاده گردید. نتایج نشان داد که کاهش چربی باعث افزایش معنی‌دار سفتی، ارتجاع‌پذیری و میزان رطوبت می شود اما چسبندگی و امتیاز پذیرش کلی نمونه های پنیر کاهش می یابد. برخلاف WPC، تیمار آنزیمی با ترانس گلوتامیناز سفتی، پیوستگی و ارتجاع‌پذیری را بطور معنی‌داری افزایش داد اما میزان رطوبت و چسبندگی پنیر را کاهش داد. در این میان آنزیم ترانس گلوتامیناز اثر معنی‌داری بر امتیاز کلی ارزیابی حسی نداشت اما خواص حسی نمونه‌های پنیر کم‌چرب با جایگزینی WPC با ناتراوه تا میزان 8% بهبود یافت. نتایج بهینه‌سازی با طرح مرکب مرکزی نشان داد که بهترین نمونه با خواص حسی و بافتی مطلوب زمانی حاصل می‌شود که فرمول پنیر شامل 95/5% چربی، 56/0 واحد آنزیم ترانس گلوتامیناز و 79/8% محلول WPC باشد.

Evolutionary-biological peculiarities of transglutaminase. Structure, physiological functions, application

Transglutaminasc (protein-glutamine gamma-glutamyltransferase, EC 2.3.2.13, TG) catalyzes reactions of the acyl transfer, which introduce the epsilon-(gamma-glutamyl)lysine bonds between proteins to create polymers of high mol. mass. Properties of the TG enzyme are described. Its structure is considered: there are characterized items of the TG life cycle and stability, its biological (physiological) role, and significance in pathology and medicine as well as obtaining of the purified enzyme preparations and their use. There are compared TG from different sources: of animal and microbial origin. Mechanism of catalysis of microbial TG is discussed. There are presented characteristics of isoenzymes from different biological sources.

Tissue transglutaminase antibodies in celiac disease: focus on the pediatric population

Celiac disease (CD) is an immune-mediated disorder induced by the ingestion of gluten in genetically susceptible individuals. The enzyme tissue transglutaminase (protein-glutamine gamma-glutamyltransferase 2; tTG) plays an important role in the pathogenesis of the disease and antibodies against tTG are used as serological markers for the diagnosis of CD. Discovery of tTG as the autoantigen for endomysial antibodies changed the diagnostic approach to patients with suspected CD and, importantly, made screening for CD more accurate and easier to perform. Studies in pediatric populations confirmed the high sensitivity and specificity of immunoglobulin A (IgA) tTG antibodies in the diagnosis of CD. The aim of this review is to summarize the data on the role of tTG in the pathogenesis of CD and to present current evidence on the accuracy of IgA tTG, IgG tTG and IgA tTG point-of-care tests in the diagnosis of CD in children. This review shows why IgA tTG antibodies replaced endomysial antibodies as the preferred serological marker due to the ease of their use, their high sensitivity and specificity, and the high correlation between high titers and intestinal mucosal lesions.

Enzymatic determination of biogenic amines with transglutaminase

Tyramine, histamine, putrescine and cadaverine, the most common biogenic amines indicating the food quality, were studied in the transglutaminase-catalyzed reaction. Transglutaminase (protein-glutamine gamma-glutamyltransferase EC 2.3.2.13) catalyzes an acyl transfer reaction between a donor substrate and an acceptor substrate (e.g. biogenic amine) and forms a cross-linkage between substrates with a release of ammonia. The reaction can be monitored by measuring the ammonia produced in the reaction. The concentration of produced ammonia was found to be proportional to the concentration of biogenic amine and could hence be used to determination of biogenic amines in food matrixes.

Complete amino acid sequence and homologies of human erythrocyte membrane protein band 4.2.

The complete amino acid sequence for human erythrocyte band 4.2 has been derived from the nucleotide sequence of a full-length 2.35-kilobase (kb) cDNA. The 2.35-kb cDNA was isolated from a human reticulocyte cDNA library made in the expression vector lambda gt11. Of the 2348 base pairs (bp), 2073 bp encode 691 amino acids representing 76.9 kDa (the SDS/PAGE molecular mass is 72 kDa). RNA blot analysis of human reticulocyte total RNA gives a message size for band 4.2 of 2.4 kb. The amino acid sequence of band 4.2 has homology with two closely related Ca2(+)-dependent cross-linking proteins, guinea pig liver transglutaminase (protein-glutamine gamma-glutamyltransferase; protein-glutamine: amine gamma-glutamyltransferase, EC 2.3.2.13) (32% identity in a 446-amino acid overlap) and the a subunit of human coagulation factor XIII (27% identity in a 639-amino acid overlap), a transglutaminase that forms intermolecular gamma-glutamyl-epsilon-lysine bonds between fibrin molecules. The region of greatest identity includes a 49-amino acid stretch of band 4.2, which is 69% and 51% identical with guinea pig liver transglutaminase and the a subunit of factor XIII, respectively, within the regions that contain the active sites of these enzymes. Significantly, within the five contiguous consensus residues of the transglutaminase active site, Gly-Gln-Cys-Trp-Val, band 4.2 has an alanine substituted for cysteine (which is apparently essential for activity). Consistent with this active site substitution, erythrocyte membranes or inside-out vesicles, which contain band 4.2, show no evidence of transglutaminase activity by two types of in vitro assay.