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Sulfation Pattern (sulfation + pattern)
Selected AbstractsRedundant function of the heparan sulfate 6-O-endosulfatases Sulf1 and Sulf2 during skeletal developmentDEVELOPMENTAL DYNAMICS, Issue 2 2008Andreas Ratzka Abstract Modification of the sulfation pattern of heparan sulfate (HS) during organ development is thought to regulate binding and signal transduction of several growth factors. The secreted sulfatases, Sulf1 and Sulf2, desulfate HS on 6-O-positions extracellularly. We show that both sulfatases are expressed in overlapping patterns during embryonic skeletal development. Analysis of compound mutants of Sulf1 and Sulf2 derived from gene trap insertions and targeted null alleles revealed subtle but distinct skeletal malformations including reduced bone length, premature vertebrae ossification and fusions of sternebrae and tail vertebrae. Molecular analysis of endochondral ossification points to a function of Sulf1 and Sulf2 in delaying the differentiation of endochondral bones. Penetrance and severity of the phenotype increased with reduced numbers of functional alleles indicating redundant functions of both sulfatases. The mild skeletal phenotype of double mutants suggests a role for extracellular modification of 6-O-sulfation in fine-tuning rather than regulating the development of skeletal structures. Developmental Dynamics 237:339,353, 2008. © 2008 Wiley-Liss, Inc. [source] Age-related changes in human meniscal glycosaminoglycansINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 4 2004Gareth Blackburn Introduction With an increased human lifespan, a major challenge is now to ensure a concomitant increase in healthspan. Meniscal damage and degradation are common and are strongly correlated with subsequent osteoarthritis. Indeed, meniscal damage has been identified in about 60% of people over 60. Markers of pathology will facilitate intervention but first require normal age-related changes to be established. Methods Undamaged vascular and avascular regions of medial and lateral human menisci were comminuted and the tissue extracted into 4- m GuHCl and subject to associative CsCl density gradient centrifugation. Aggrecan and the small leucine rich PGs (SLRPs) were isolated and their GAG profiles examined by HPAEC fingerprinting, following enzyme depolymerization, and by an NMR spectroscopy. Results and discussion Analysis of aggrecan and the SLRPs show that there is a complex and dynamic pattern of KS, CS and DS abundance and distribution within human menisci, which changes with age. The abundance of SLRPs is higher in the avascular than vascular tissues, however, this is not reflected in the abundance of aggrecan which is present at similar levels in both tissue regions. The data show no other significant differences between medial and lateral and between vascular and avascular tissue regions. Analysis of the sulfation pattern of CS following digestion by ACII lyase, shows that in both aggrecan and SLRPs the 4-sulfation level falls with age from 20 to 35% in young tissues to 10,20% in older. Subsequent analyses following ABC lyase depolymerization, to include DS, shows very significant change with age from CS + DS 4-sulfation levels of ca. 40,55% in young tissue to ca. 15,30% in older. The difference between these datasets represents the contribution made by 4-sulfated DS. Thus, analysis of the difference suggests that DS makes a decreasing contribution to the CS/DS profile with age. Indeed, this is confirmed by an NMR analysis of these samples. Analysis of the resonances in the region 1.95,2.2 p.p.m. (ref to TSP) allows the estimation of the contribution made by DS, CS and KS. These data show that, in aggrecan, the contribution made by DS chains falls from ca. 10% in younger tissues to ca. 2,4% in older tissues. NMR analysis also shows that KS levels fall with age from ca. 15,20% in younger tissues to 5,10% in older tissues. Analysis of the structure of the KS chains shows chains with a structure similar to that of in articular cartilage but that at all ages there are very low levels of fucosylation (ca. 1,5%). Previous studies of age-related changes in CS/DS and KS structures have shown significant changes in the first 17 years of life, with only modest nonpathological changes after that time. These data from meniscal tissues do not show such a dramatic halting of normal age-related changes. Indeed, the data show gradual age-related changes in DS, CS and KS abundance and structure throughout life. These baseline age-related changes data will now allow the analysis of pathology-related changes. [source] Steam reactivation of a spent sorbent for enhanced SO2 capture in FBCAICHE JOURNAL, Issue 12 2006Fabio Montagnaro Abstract The regeneration by steam hydration of the sulfur capture ability of spent sorbent particles from Fluidized Bed Combustion (FBC) is addressed. The process is characterized in terms of effectiveness of sorbent reactivation, hydration degree, particle sulfation pattern, development of accessible porosity, and extent of particle attrition and fragmentation. Steam reactivation experiments were carried out in a lab-scale atmospheric FBC at 250°C for 10, 30, and 180 min with 0.05 MPa steam partial pressure. The effectiveness of sorbent reactivation was assessed by reinjecting the reactivated material into the FB reactor operated at 850°C under simulated desulfurization conditions and following the degree of calcium conversion and the attrition rate along with resulfation. The experimental results indicated that steam reactivation is effective in renewing the SO2 uptake ability of the exhausted sorbent particles. The regeneration mechanism based on the swelling upon hydration of the unreacted core, the generation of fissures and cracks, and the consequent development of accessible porosity is confirmed for the limestone under scrutiny. In addition to this, a remarkable result was that steam hydration induces, for the sorbent under investigation, a pronounced sulfur redistribution throughout the particle cross-section, which provides another pathway to the enhancement of the sulfur capture ability of the reactivated sorbent. © 2006 American Institute of Chemical Engineers AIChE J, 2006 [source] Analysis of glycosaminoglycan-derived disaccharides in biologic samples by capillary electrophoresis and protocol for sequencing glycosaminoglycansBIOMEDICAL CHROMATOGRAPHY, Issue 2 2002F. N. Lamari Glycosaminoglycans are biologically significant carbohydrates which either as free chains (hyaluronan) or constituents of proteoglycans (chondroitin/dermatan sulfates, heparin, heparan sulfate and keratan sulfate) participate and regulate several cellular events and (patho)physiological processes. Capillary electrophoresis, due to its high resolving power and sensitivity, has been successfully used for the analysis of glycosaminoglycans. Determination of compositional characteristics, such as disaccharide sulfation pattern, is a useful prerequisite for elucidating the interactions of glycosaminoglycans with matrix effective molecules and, therefore, essential in understanding the biological functions of proteoglycans. The interest in the field of characterization of such biologically important carbohydrates is soaring and advances in this field will signal a new revolution in the area of glycomics equivalent to that of genomics and proteomics. This review focuses on the capillary electrophoresis methods used to determine the disaccharide pattern of glycosaminoglycans in various biologic samples as well as advances in the sequence analysis of glycosaminoglycans using both chromatographic and electrophoretic techniques. Copyright © 2002 John Wiley & Sons, Ltd. [source] Microscale characterization of the binding specificity and affinity of a monoclonal antisulfotyrosyl IgG antibodyELECTROPHORESIS, Issue 12 2008Klaus S. Lassen Dr. Abstract Sulfation is a potentially important post-translational modification of proteins and has been demonstrated in a number of polypeptides, notably in gastrointestinal hormones. In contrast to phosphorylation, however, the investigation of sulfation patterns in tissues and on purified proteins has been complicated by the absence of specific immunoreagents (antibodies) for this modification as well as the chemical lability of the sulfate group. Here, we investigate the properties of a novel mAb against sulfated tyrosyl groups (anti-Tyr(SO3H) antibody) using CE and a panel of sulfated and nonsulfated peptides and proteins. The data show that the anti-Tyr(SO3H) antibody is completely specific for compounds containing sulfated tyrosyls. Affinity electrophoresis experiments allowed us to estimate dissociation constants for sulfated hirudin fragment (56,65), gastrin-17, and cholecystokinin octapeptide (CCK8) in the 1,3,,M range. The affinity of the antibody toward complement 4 protein that contains three sulfotyrosines was analyzed by surface plasmon resonance technology and modeled according to a bivalent-binding model which yielded a Kd1 of 20.1,,M for the monovalent complex. The same binding was studied by CE and found to be in the micromolar scale albeit with some uncertainty due to complex separation patterns. The work illustrates the amount of information on antibody,antigen interactions that may be obtained with microelectrophoretic methods consuming minute quantities of material. Furthermore the specificity of this antibody could be confirmed in one operation using an array of sulfated and nonsulfated compounds. [source] The effects of age and sex on chondroitin sulfates in normal synovial fluidARTHRITIS & RHEUMATISM, Issue 8 2002Yoshihito Nakayama Objective To examine how age and sex influence chondroitin sulfates (CS) in normal synovial fluid, we measured the concentrations of chondroitin 6-sulfate (C6S), chondroitin 4-sulfate (C4S), and hyaluronic acid (HA) in healthy subjects of different ages. Methods Synovial fluid samples were obtained from 82 healthy volunteers, ages 20,79 years. Results The concentrations of CS and HA and the C6S:C4S ratio varied with age. Their values were highest between 20 and 30 years of age, and thereafter they showed a tendency to decrease. Statistically, the C6S concentration and the C6S:C4S ratio at ages 60,70 years were significantly lower than those at 20,30 years of age. There was also a clear between-sex difference, in which the CS concentrations and the C6S:C4S ratio in women were significantly lower than those in men (P = 0.0003 for C6S, P = 0.02 for C4S, P = 0.002 for C6S:C4S ratio). In sharp contrast, little between-sex difference was found in the HA concentration. In multiple regression analysis, age correlated strongly with the C6S concentration and the C6S:C4S ratio (r = ,0.521 and r = ,0.617, respectively), weakly with the C4S concentration (r = ,0.202), and moderately with the HA concentration (r = ,0.483). Sex showed a weak correlation with the concentrations of C6S and C4S and the C6S:C4S ratio (r = 0.307, r = 0.225, and r = 0.237, respectively), and little correlation was seen between sex and the HA concentration. Conclusion The CS concentrations and the sulfation patterns in normal synovial fluid vary with age and sex, and these physiologic variations need to be taken into account when using synovial fluid CS as markers for arthritic conditions. [source] Preparation and Use of Microarrays Containing Synthetic Heparin Oligosaccharides for the Rapid Analysis of Heparin,Protein InteractionsCHEMISTRY - A EUROPEAN JOURNAL, Issue 34 2006Christian Noti Abstract Heparin is a highly sulfated, linear polymer that participates in a plethora of biological processes by interaction with many proteins. The chemical complexity and heterogeneity of this polysaccharide can explain the fact that, despite its widespread medical use as an anticoagulant drug, the structure,function relationship of defined heparin sequences is still poorly understood. Here, we present the chemical synthesis of a library containing heparin oligosaccharides ranging from di- to hexamers of different sequences and sulfation patterns. An amine-terminated linker was placed at the reducing end of the synthetic structures to allow for immobilization onto N -hydroxysuccinimide activated glass slides and creation of heparin microarrays. Key features of this modular synthesis, such as the influence of the amine linker on the glycosidation efficiency, the use of 2-azidoglucose as glycosylating agents for oligosaccharide assembly, and the compatibility of the protecting group strategy with the sulfation-deprotection steps, are discussed. Heparin microarrays containing this oligosaccharide library were constructed using a robotic printer and employed to characterize the carbohydrate binding affinities of three heparin-binding growth factors. FGF-1, FGF-2 and FGF-4 that are implicated in angiogenesis, cell growth and differentiation were studied. These heparin chips aided in the discovery of novel, sulfated sequences that bind FGF, and in the determination of the structural requirements needed for recognition by using picomoles of protein on a single slide. The results presented here highlight the potential of combining oligosaccharide synthesis and carbohydrate microarray technology to establish a structure,activity relationship in biological processes. [source] | ||||||||||||||||