Journal of glycomics & lipidomics最新文献

{"title":"Naturally Occurring Follicle-Stimulating Hormone Glycosylation Variants.","authors":"John S Davis, T Rajendra Kumar, Jeffrey V May, George R Bousfield","doi":"10.4172/2153-0637.1000e117","DOIUrl":"https://doi.org/10.4172/2153-0637.1000e117","url":null,"abstract":"Follicle-stimulating hormone (FSH) is a member of the glycoprotein hormone family, which is a subfamily of the cystine knot growth factor superfamily [1,2]. The glycoprotein hormones are composed of heterodimeric glycoprotein subunits, a common α-subunit, and a hormone-specific β-subunit. While the α-subunit primary structure is identical for all glycoprotein hormones within the same species, the oligosaccharide populations differ in a hormone-specific manner [3–6]. Characterizing the oligosaccharides released from an α-subunit preparation can identify the hormone from which the subunit was derived [7]. There are 3 to 4 β-subunits in vertebrates, which combine with α-subunit to create either FSH, luteinizing hormone (LH), thyroid-stimulating hormone (TSH), or in primates and equids, chorionic gonadotropin (CG) [8]. As both glycoprotein hormone subunits are cystine knot proteins [9–11] the protein backbone is folded into a series of three loops, two relatively rigid hairpin loops on one side of the knot, designated L1 and L3, and a single, flexible loop on the other side [12], designated L2. Oligosaccharides are attached to all 3 loops in a subunit-specific pattern (Figure 1). FSH subunits possess two potential N-glycosylation sites on each subunit and all four are of the Asn-Xaa-Thr type, which exhibit very efficient carbohydrate attachment [13]. Indeed, the α-subunit is always glycosylated at both sites in all known glycoprotein hormones. Because FSH α and β subunits co-migrate during electrophoresis, it is difficult to detect missing N-glycans in this hormone. FSHβ-specific Western blots have revealed partial glycosylation in equine FSHβ, human FSHβ (hFSH β), rhesus FSH β, and Japanese macaque FSHβ [14–16]. During the past few years, we have studied partially glycosylated hFSH isolated from pituitary extracts, postmenopausal urine, and conditioned tissue culture medium containing recombinant hFSH. Each glycosylation site in hFSH is decorated with a population of N-glycans. When total glycans are removed from reduced, carboxy-methylated FSH subunits, 39–130 glycans are found in mass spectra. We have data from only one glycosylation site, αAsn52, which possessed 29 neutral core ions, and when decorated with various patterns of sialic acid grew to 109 unique glycan structures. Micro heterogeneity can affect electrophoretic mobility, for example, placental hCGα with hybrid and biantennary glycans migrated faster than pituitary hFSHα, with triantennary, biantennary and tetraantennary glycans, which complicated sorting out the hFSH variants that resulted from loss of one or more N-glycans [17].","PeriodicalId":89585,"journal":{"name":"Journal of glycomics & lipidomics","volume":"4 1","pages":"e117"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4172/2153-0637.1000e117","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33109412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Omega-3 Polyunsaturated Fatty Acids for Treatment of Nonalcoholic Fatty Liver Disease: A Possible Case for Personalized Therapy","authors":"R. Siddiqui, K. Harvey","doi":"10.4172/2153-0637.1000E118","DOIUrl":"https://doi.org/10.4172/2153-0637.1000E118","url":null,"abstract":"In a recent issue of PLOSone Depner et al. [1] reported an excellent study on omega-3 fatty acid-induced changes in lipid metabolomics that may be involved in attenuating western diet-induced nonalcoholic steatohepatitis (NASH). A western diet, which is typically rich in saturated and trans fats, that leads to fat accumulation in the liver. This condition resembles alcoholic fatty liver disease; however, it progresses in the absence of any alcohol intake and is known as nonalcoholic fatty liver disease (NAFLD) [2]. In most individuals, the liver is devoid of any symptoms or problems that will only culminate in mild steatosis. However, in some cases, especially individuals with obesity and metabolic syndrome, the fat accumulation is accompanied with inflammation and causes NASH. If untreated, NASH worsens and causes fibrosis resulting in scarring of the liver. The pathophysiologic pathway of NAFLD is not clearly elucidated. Day and James [3] in 1998 proposed the “two-hit phenomenon,” where the “first hit” consists of triglyceride (TG) depositions in hepatocytes causing cellular dysfunction and death (lipotoxicity). The hyperinsulinemia and insulin resistance play a role in the first hit causing an alteration in uptake, synthesis, degradation, and secretion of free fatty acids leading to an accumulation of fat in hepatocytes, or steatosis [4,5]. Steatosis by itself is not detrimental, but the steatotic liver becomes more vulnerable to “second hits” by inflammatory cytokines, endotoxins, and oxidative stress causing mitochondrial dysfunction, which ultimately results in hepatocyte injury and fibrosis [6]. NAFLD is also associated with an increased risk of cardiovascular disease (CVD). To date there is no standardized optimal treatment, although several approaches to treat NAFLD have been adopted, including weight reduction, limiting dietary carbohydrate intake, inhibiting fat absorption by sibtramine and orlistat, lowering lipid profile by statins, improving insulin sensitivity by Metformin and thioglitazone and reducing oxidative stress by vitamin E [7-9].","PeriodicalId":89585,"journal":{"name":"Journal of glycomics & lipidomics","volume":"4 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70233273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Macro- and Micro-heterogeneity in Pituitary and Urinary Follicle-Stimulating Hormone Glycosylation.","authors":"George R Bousfield,&nbsp;Vladimir Y Butnev,&nbsp;Monica A Rueda-Santos,&nbsp;Alan Brown,&nbsp;Aaron Smalter Hall,&nbsp;David J Harvey","doi":"10.4172/2153-0637.1000125","DOIUrl":"https://doi.org/10.4172/2153-0637.1000125","url":null,"abstract":"<p><p>FSH glycosylation macroheterogeneity in pituitary and urinary hFSH samples was evaluated by Western blotting. Microheterogeneity in two highly purified urinary and pituitary hFSH preparations was evaluated by nano-electrospray mass spectrometry of peptide-N-glycanase-released oligosaccharides. An age-related loss of hypo-glycosylated hFSH in individual female pituitaries was indicated by progressively reduced abundance of hFSH²¹ relative to hFSH²⁴. Urinary hFSH was evaluated as a potentially non-invasive indicator of glycoform abundance, as the only way for pituitary FSH to reach the urine is through the blood. Both highly purified and crude postmenopausal urinary hFSH preparations possessed the same amount of hFSH²¹ as postmenopausal pituitary gland FSH. Considerable microheterogeneity was encountered in both pituitary and urinary hFSH glycan populations, as 84 pituitary hFSH glycan ions were observed as compared with 68 urinary hFSH glycans. The biggest quantitative differences between the two populations were reduced abundance of bisecting GlcNAc-containing and fucosylated glycans, along with sulfated glycans in the urinary hFSH glycan population. The relative abundance of sialic acid and glycan antenna did not rationalize the retarded electrophoretic mobilities of the urinary hFSHβ²¹- and α-subunit bands relative to the corresponding pituitary hFSH bands, as the most abundant glycans in the former possessed only 2 more branches and the same sialic content as in the latter. Site-specific glycosylation information will probably be necessary.</p>","PeriodicalId":89585,"journal":{"name":"Journal of glycomics & lipidomics","volume":"4 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4172/2153-0637.1000125","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33088324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Glycokinomics: Emerging Therapeutic Approaches for Malignant Brain Tumors","authors":"Roger AKroes, J. Moskal","doi":"10.4172/2153-0637.1000109","DOIUrl":"https://doi.org/10.4172/2153-0637.1000109","url":null,"abstract":"The oligosaccharide chains, or glycans, that decorate cell surface glycoproteins and glycolipids are among the most complex and diverse structures in vertebrate cells. It is estimated the well over half of all human proteins are glycosylated. Their expression is exquisitely regulated and is the result of the coordinated activity of distinct glycosyltransferases and glycosyl hydrolases that add or remove individual sugars to complete each glycan chain. Aberrantly expressed cell surface glycoconjugates are associated with malignant transformation, tumor progression, and metastasis and are predominantly the result of alterations in their biosynthetic machinery. They mediate key pathophysiological events during tumorigenesis including altered cellular adhesion and invasivity, molecular trafficking, receptor activation, and intracellular signal transduction in tumors.","PeriodicalId":89585,"journal":{"name":"Journal of glycomics & lipidomics","volume":"2013 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2013-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70229683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"N- and O-glycome analysis of serum and urine from bladder cancer patients using a high-throughput glycoblotting method","authors":"M. Takeuchi, M. Amano, H. Kitamura, T. Tsukamoto, N. Masumori, K. Hirose, Tetsu Ohashi, S. Nishimura","doi":"10.4172/2153-0637.1000108","DOIUrl":"https://doi.org/10.4172/2153-0637.1000108","url":null,"abstract":"Purpose: To develop novel diagnostic biomarkers for Bladder Cancer (BC), we concurrently evaluated serum and urine glycans in BC patients by utilizing a recently established glycoblotting method. \u0000Experiments: N- and O-glycan levels in whole serum from 45 and 13 male patients diagnosed with BC were analyzed. As a control, 29 and 10 patients with benign prostatic hyperplasia (BPH) were also studied and the results were compared. Furthermore, urine N- and O-glycome from 8 patients with muscle-invasive BC and 11 with BPH were analyzed. In serum N-glycome analysis the area-under-the-curve (AUC) value was calculated by in house R software. In the other cases JMP, version 10.0.2 software package (SAS, Cary, NC) was used and p <0.05 was considered statistically significant. \u0000Results: The expression level of three N-glycans significantly increased in sera of BC patients. All of them had highly branched and sialylated structures with core-Fuc. The levels of three O-glycans were significantly higher in BC than in the control. In examination of urine samples, 16 N-glycans were significantly elevated in BC as compared to the control. Although 11 O-glycans were detected in urine samples, there was no significant difference in the expression levels. \u0000Conclusions: The levels of highly branched, sialylated N-glycans and early sialylated O-glycans were increased in sera of BC patients. Moreover, we found that N-glycans increased in urine more than in serum of BC patients. These results suggest that the glycome change in urine directly results from glycoproteins that exist in BC cells. Thus, further large-scale glycan profiling will provide novel biomarkers for diagnosing BC in the near future.","PeriodicalId":89585,"journal":{"name":"Journal of glycomics & lipidomics","volume":"52 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2013-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70230092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lipid Triad: An Important Predictor of Dyslipidemia Related Disorders and its Therapeutic Intervention","authors":"Shafeeque Ahmad, M. Hossain, Muhammad Anas","doi":"10.4172/2153-0637.1000E114","DOIUrl":"https://doi.org/10.4172/2153-0637.1000E114","url":null,"abstract":"Cardiovascular disease (CVD) is leading cause of premature death worldwide. 30% of all global deaths in 2005, i.e. 17.5 million people died from this CVD. If proper and quick actions are not taken, an estimated number of 20 million people will die by 2015, including stroke [1]. Lavie et al. [2] stated regarding fiscal burden of CVD and, especially, coronary heart disease (CHD), most medical treatments are directed at the major CHD risk factors. CVD implies to any medical disorders related to heart and blood vessels. There are a number of known causative factors that are directly or indirectly responsible for CVD. The lipid triad refers basically to three lipid abnormalities: increased plasma triglycerides and small dense low density lipoprotein (sd-LDL), and decreased high density lipoprotein cholesterol (HDL-C) concentrations. Since lipid triad is highly atherogenic in nature causing CVD, also called as atherogenic lipoprotein phenotype. The liver secretes lipoproteins called very-low-density lipoproteins (VLDL) rich in triglycerides. As these lipoproteins come into contact with lipoprotein lipase situated on capillary endothelial cell, hydrolyzes the triglycerides leaving VLDL remnant. Many patients with premature CHD having cholesterol levels in the range of 200-240 mg/dl show other risk factors like hypertension, obesity or abnormalities in triglycerides metabolism. But these above anomalies are often seen in reduced concentration of HDL [3]. Low density lipoprotein cholesterol (LDL-C) rich in cholesterol has been extensively studied and known for its bad cholesterol because it is considered as a good marker for cardiovascular disease risk assessment [4] and its level in human body should be below 130 mg/dl. HDL-C ranging between 35-40 mg/dl is considered as good cholesterol as it helps in the removal of cholesterol along with it also shows antioxidant property carrying arylesterase/ paraoxonase antioxidant enzyme. High level about 60 mg/dl of HDL-C is believed to be played a good protective role in human health protection as it protects efficiently heart from dangerous attack on it. The various previous studies clearly indicate that high concentration of LDL-C and substantially increased ratio of LDL and HDL are important risk factors which promote atherosclerosis [5]. The study for UK Progression of Diabetes Study showed that LDL-C is the strongest risk factor for coronary heart disease followed by HDL-C in this population [6]. Thus it suggested that 0.1 mM rise in HDL-C would decrease coronary heart disease by 15%. LDL particles are differentiated into large buoyant LDL (lb-LDL) and small dense LDL (sd-LDL). These subfractions are associated with difference in size, density, physico-chemical composition, metabolic behavior and atherogenicity. Different known techniques such as density gradient, ultracentrifugation, polyacrylamide gel electrophoresis, nuclear magnetic resonance, etc. are employed for fractionation of LDL into sd-LDL and lb-","PeriodicalId":89585,"journal":{"name":"Journal of glycomics & lipidomics","volume":"3 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2013-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70233353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metabolic Profiling and Quantification of Sphingolipids by Liquid Chromatography-Tandem Mass Spectrometry","authors":"Wujuan Zhang, B. Quinn, Sonya Barnes, G. Grabowski, Ying Sun, K. Setchell","doi":"10.4172/2153-0637.1000107","DOIUrl":"https://doi.org/10.4172/2153-0637.1000107","url":null,"abstract":"A precise, robust, and specific liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) method was developed for profiling and quantifying glucosyl sphingosine (GS), glucosylceramide (GC), ceramide (Cer), lactosylceramide (LacCer) and sulfatide lipid species in a variety of mouse tissues. The linear response ranges of these species were 0.05-25 ng. The major GC species identified in visceral tissues of mice were GCs with N-acyl chains of C24-1, C24, C22, C16 lengths, but the qualitative and quantitative profiles differed among tissues. GC levels in spleen were approximately 3-5 times higher than in liver and lung. Brain differed from visceral tissues in that galactosylceramides (GalCer) were the predominant monohexosylceramide species identified. A silica column used in hydrophobic interaction liquid chromatography (HILIC) mode was capable of differentiating GC and GalCer. The analysis of mouse brain samples revealed that GC accounted for only 0.3% of the total monohexosylceramides. Cer and LacCer were also profiled and quantified in mouse brain, lung, liver and spleen. Application of these methods greatly facilitated a range of targeted sphingolipidomic investigations and will permit a better understanding of the function and mechanism of these diverse molecular species in various disease animal models, including Gaucher disease.","PeriodicalId":89585,"journal":{"name":"Journal of glycomics & lipidomics","volume":"3 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2013-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4172/2153-0637.1000107","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70230043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Statin Therapy and Tendon Disorders","authors":"L. P. Oliveira, C. P. Vieira, F. Guerra, Marcos dos Santos Almeida, E. Pimentel","doi":"10.4172/2153-0637.1000E115","DOIUrl":"https://doi.org/10.4172/2153-0637.1000E115","url":null,"abstract":"The 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase is an enzyme that catalyzes the conversion of HMG-CoA to mevalonic acid, a precursor of cholesterol. This enzyme is a target for pharmacological intervention since it acts on cholesterol biosynthesis. At the cellular level, statins inhibit the conversion of HMG-CoA to mevalonic acid, and as a result, inhibit cholesterol synthesis in the liver [2].","PeriodicalId":89585,"journal":{"name":"Journal of glycomics & lipidomics","volume":"10 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2013-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70233488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MALDI-TOF MS: Much More than only Protein Analysis!","authors":"B. Fuchs, J. Schiller","doi":"10.4172/2153-0637.1000E113","DOIUrl":"https://doi.org/10.4172/2153-0637.1000E113","url":null,"abstract":"Carbohydrates and particularly lipids represent molecules with significant structural variabilities: this is stemming from (a) the headgroups, (b) the different fatty acyl residues and (c) the linkage types (acyl-acyl-, alkyl-acyl-, and alkenyl-acyl-). Therefore, analytical methods to clarify these aspects are of immense significance. As the amount of the available biological material is normally limited, suitable methods should also exhibit reasonable sensitivities. It is our aim to introduce MALDI (matrix-assisted laser desorption and ionization) MS (mass spectrometry) [1] (often but not necessarily with a time-offlight (TOF) mass analyzer) as a simple and sensitive analytical method that helps to overcome many problems related to carbohydrate and particularly lipid analysis [2]. Although the history of MS dates back to the end of the nineteenth century, applications of MS to the structural analysis of biomolecules are rather new: the MS analysis of such complex molecules (often in combination with high polarity and low volatility) became only possible with the invention of “soft ionization” methods such as electrospray ionization (ESI) and “MALDI” [3]. Both techniques are nowadays widely used, whereby the focus is often on the investigation of proteins - normally subsequent to enzymatic digestion of the (unknown) protein into characteristic peptides, the MS of which enables the elucidation of the protein sequence and further structural properties [4]. It is a characteristic property of “soft ionization” MS that there is only a small extent of analyte fragmentation and, thus, the intact ions of the analyte of interest can be observed. This is a pronounced difference in comparison to the classical “electron ionization” (EI) technique. Although MALDI MS has many advantages it should be noted that the analysis of small molecules (for instance, free fatty acids) is still a problem - despite many improvements that could be recently achieved [5]. This problem with small molecules can be easily understood when the principle of MALDI MS is considered: MALDI MS is based on laser ionization, whereby normally UV lasers (emitting often at λ=337 nm) are used. Since not all potential analytes exhibit a sufficient absorption at this wavelength, a “matrix” must be used [1]. This matrix is normally a small organic molecule (such as 2,5-dihydroxybenzoic acid (DHB)) [6] that absorbs the laser energy, is evaporated and simultaneously carries the analyte into the gas phase (high vacuum). In the gas phase collisions between the analyte and cations (such as H + or Na + ), that are either already present in the lipid extract of interest or artificially added, occur leading to ion generation. As the mass of the observed (positive) ions is slightly higher than the mass of the analyte, these are normally termed “adducts” or “quasimolecular” ions. Of course, analytes with acidic groups are also detectable as negative ions. Since the matrix is normally in considerable exce","PeriodicalId":89585,"journal":{"name":"Journal of glycomics & lipidomics","volume":"2013 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2013-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70233179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Analysis of N-glycans attached to Pig Kidney Na+/K+-ATPase","authors":"M. Kanagawa, Kana Matsumoto, Noriyuki Iwasaki, Y. Hayashi, Y. Yamaguchi","doi":"10.4172/2153-0637.S5-005","DOIUrl":"https://doi.org/10.4172/2153-0637.S5-005","url":null,"abstract":"Na+/K+-ATPase is a membrane glycoprotein composed of α, β, and γ subunits, generating ion gradients across plasma membranes. Ion pumping is mainly accomplished by the α subunit, while the glycosylated β subunit binds tightly to the α subunit to assemble the pump and plays an essential role in the stabilization and maturation of Na+/K+-ATPase. Accumulating evidence suggests that the N-glycans of the β subunit contribute to cell-cell interaction and the tightness of cell contacts is modulated by N-glycan branching. However, N-glycan function is not fully understood due to a lack of detailed information on the oligosaccharide structure. We, here, perform glycosylation profi ling of the N-glycans attached to pig kidney Na+/K+-ATPase in order to better understand the mechanism of Na+/K+-ATPase-mediated cell adhesion. \u0000We purifi ed Na+/K+-ATPase from pig kidney outer medulla to homogeneity and solubilized it with the detergent C12E8. The enzyme thus obtained was identifi ed as α1β1 subtype by LC-MS/MS analysis of tryptic digests. During the course of MS analysis, we found that Lys456 of the α subunit was partially modifi ed with 4-hydroxynonenal, an aldehydric lipid peroxidation product. Three N-glycosylation sites on the β1 subunit were confi rmed to be fully occupied by time course analysis of enzymatic deglycosylation monitored by SDS-PAGE. HPLC profi ling of pyridylaminated oligosaccharides derived from Na+/K+-ATPase showed that high-mannose type oligosaccharides predominate while most of the less abundant complex-type oligosaccharides are capped with galactose residues. No glycans could be detected on the four consensus N-glycosylation sites on the α1 subunit. We briefl y discuss the possibility that oligomerization of Na+/K+- ATPase via β-β interactions assembles the N-glycans and promotes cell-cell adhesion.","PeriodicalId":89585,"journal":{"name":"Journal of glycomics & lipidomics","volume":"2012 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2013-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70234896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}