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1.
Acta Trop ; 252: 107142, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38331083

ABSTRACT

Helminth parasites modulate the host immune system to ensure a long-lasting asymptomatic form of infection generally, mediated by the secretion of immunomodulatory molecules and one such molecule is a homologue of human host cytokine, Macrophage migratory Inhibitory Factor (hMIF). In this study, we sought to understand the role of homologue of hMIF from the lymphatic filarial parasite, Wuchereria bancrofti (Wba-MIF2), in the immunomodulation of the Streptozotocin (STZ)-induced Type1 Diabetes Mellitus (T1DM) animal model. Full-length recombinant Wba-MIF2 was expressed and found to have both oxidoreductase and tautomerase activities. Wba-MIF2 recombinant protein was treated to STZ induced T1DM animals, and after 5 weeks pro-inflammatory (IL-1, IL-2, IL-6, TNF-α, IFN-γ) and anti-inflammatory (IL-4, IL-10) cytokines and gene expressions were determined in sera samples and spleen respectively. Pro-inflammatory and anti-inflammatory cytokine levels were significantly (p<0.05) up-regulated and down-regulated respectively, in the STZ-T1DM animals, as compared to treated groups. Histopathology showed macrophage infiltration and greater damage of islets of beta cells in the pancreatic tissue of STZ-T1DM animals, than Wba-MIF2 treated STZ-T1DM animals. The present study clearly showed the potential of Wba-MIF2 as an immunomodulatory molecule, which could modulate the host immune system in the STZ-T1DM mice model from a pro-inflammatory to anti-inflammatory milieu.


Subject(s)
Diabetes Mellitus, Experimental , Diabetes Mellitus, Type 1 , Filarioidea , Macrophage Migration-Inhibitory Factors , Parasites , Humans , Animals , Mice , Wuchereria bancrofti , Macrophage Migration-Inhibitory Factors/genetics , Macrophage Migration-Inhibitory Factors/metabolism , Parasites/metabolism , Streptozocin , Immunologic Factors , Diabetes Mellitus, Experimental/genetics , Anti-Inflammatory Agents , Intramolecular Oxidoreductases
2.
Ned Tijdschr Tandheelkd ; 125(11): 593-601, 2018 11.
Article in Dutch | MEDLINE | ID: mdl-30457580

ABSTRACT

Evidence-based reviews of drugs causing medication-induced salivary gland dysfunction, such as xerostomia (sensation of oral dryness) and subjective sialorrhea are lacking. To compile a list of medicaments that influence salivary gland function, electronic databases were searched for relevant articles published up to June 2013. A total of 269 papers out of 3,867 records located satisfied the inclusion criteria (relevance, quality of methodology, strength of evidence). A total of 56 active substances with a higher level of evidence and 50 active substances with a moderate level of evidence of causing salivary gland dysfunction are described in this article. While xerostomia was a commonly reported outcome, the objective effect on salivary secretion was rarely measured. Xerostomia was, moreover, mostly reported as a negative side effect instead of the intended effect of that drug. A comprehensive list of medications having documented effects on salivary gland function or symptoms was compiled, which may assist practitioners in assessing patients who complain of dry mouth while taking medications.


Subject(s)
Salivary Glands/drug effects , Xerostomia/etiology , Humans
3.
Chem Sci ; 9(22): 5106-5111, 2018 Jun 14.
Article in English | MEDLINE | ID: mdl-29938042

ABSTRACT

The laminated structure of graphene oxide (GO) confers unique interactions with water molecules which may be utilised in a range of applications that require materials with tuneable hygroscopic properties. The precise role of the expandable interlayer spacing and functional groups in GO laminates has not completely been understood to date. Herein, we report the experimental and theoretical investigations on the adsorption and desorption behaviour of water in GO laminates as a function of relative pressure. We observed that GO imparts high water uptake capacity of up to 0.58 gram of water per gram of GO (g g-1), which is significantly higher than silica gel as a conventional desiccant material. More interestingly, the adsorption and desorption kinetics of GO is five times higher than silica gel. The observed extraordinary adsorption/desorption rate can be attributed to the high capillary pressure in GO laminates as well as micro meter sized tunnel-like wrinkles located at the surface.

4.
Sci Rep ; 8(1): 6038, 2018 Apr 11.
Article in English | MEDLINE | ID: mdl-29643439

ABSTRACT

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

5.
RSC Adv ; 8(41): 23130-23151, 2018 Jun 21.
Article in English | MEDLINE | ID: mdl-35540136

ABSTRACT

Many materials with varied characteristics have been used for water purification and separation applications. Recently discovered graphene oxide (GO), a two-dimensional derivative of graphene has been considered as a promising membrane material for water purification due to its excellent hydrophilicity, high water permeability, and excellent ionic/molecular separation properties. This review is focussed on the possible versatile applicability of GO membranes. It is also known that selective reduction of GO results in membranes with a pore size of ∼0.35 nm, ideally suited for desalination applications. This article presents the applicability of graphene-based membranes for multiple separation applications. This is indeed the first review article outlining a comparison of GO and r-GO membranes and discussing the suitability for applications based on the porosity of the membranes.

6.
Sci Rep ; 7(1): 14439, 2017 10 31.
Article in English | MEDLINE | ID: mdl-29089526

ABSTRACT

The unique hydrographic setting of the Bay of Bengal (BoB) makes it an ideal tropical marine system to study the influence of regional and global forcings on productivity and [CO2aq] through the late quaternary. Enormous fresh water flux into the BoB and consequent salinity stratification significantly weaken the convective mixing and wind driven processes which are commonly responsible for transport of nutrients to the euphotic zone driving primary productivity. Here we present a high resolution organic carbon-CaCO3 MAR and δ13CTOC records for the last 300 ky from the BoB. The results show significant productivity variation at marine isotope sub-stages and millennial timescales. Colder sub-stages and stadials (Dansgard-Oeschger cycle) show a boost in productivity which may be attributed to thinning of low salinity cap, thereby facilitating efficient nutrient transport across the euphotic zone by the combination of wind driven processes (entrainment and upwelling), convective mixing and cold core eddies. The [CO2aq] was a net result of global pCO2 variation and regional processes. Our long term high-resolution data indicates a possibility of marked change in productivity/biogeochemistry of BOB in the future due to global warming, thus affecting the coastal economy.

7.
Indian J Public Health ; 61(3): 174-181, 2017.
Article in English | MEDLINE | ID: mdl-28928300

ABSTRACT

BACKGROUND: The global resurgence of rickettsial diseases and their potential to impact the fitness of military personnel and inflict widespread casualties amongst civil populations has emerged as a major cause of public health concern. Absence of surveillance system, lack of awareness amongst medical fraternity to rickettsial activity along with the difficulty in diagnosis because of their protean clinical manifestations are reasons for the outbreaks of these diseases. OBJECTIVES: To determine rickettsial activity amongst rodents and study vector diversity, abundance and their distribution to enable mapping of rickettsial hotspots. METHODS: Zoonotic surveillance was undertaken in six selected study areas in India - Jammu, Akhnoor, Rajouri-Poonch, Udhampur-Nagrota, Dehradun and Pune. Weil-Felix test was used for rickettsial sero-surveillance amongst rodents and standard identification keys were used for mapping vector diversity and database preparation. RESULTS: Serological findings revealed positivity to all the three rickettsial antigens (OXK, OX19 and OX2) in Jammu, OX19 in Dehradun and OXK and OX2 positivity in Udhampur-Nagrota belt. The vector database records presence of 16 species of trombiculid mites from three important genera - Leptotrombidium, Schoengastiella and Gahrliepia with ticks from five genera and 8 species of fleas from four genera. Mite fauna of study sites has been enriched with addition of new records of mite species (five mite species at Pune, two at Akhnoor with one mite species each at Jammu and Dehradun). CONCLUSION: The study reveals rickettsial activity amongst rodents at Jammu, Dehradun and Udhampur-Nagrota belt. The results correlate well with the presence of vectors of scrub and tick typhus and corroborate the occurrence of outbreaks of these diseases in the respective areas.


Subject(s)
Disease Vectors , Rickettsia Infections/epidemiology , Rickettsia/isolation & purification , Zoonoses , Animals , Disease Reservoirs , India/epidemiology , Rodentia/microbiology , Rodentia/parasitology
8.
Phys Chem Chem Phys ; 19(8): 6051-6056, 2017 Feb 22.
Article in English | MEDLINE | ID: mdl-28191577

ABSTRACT

Defects are no longer deemed an adverse aspect of graphene. Contrarily, they can pave ways of extending the applicability of graphene. Herein, we discuss the effects of three types of defects in graphene including carbon deficiency, adatom (single Fe) dopants and the introduction of functional groups (carbonyl, ether group) on the NO2 gas adsorption via density functional theory methods. We have observed that introducing Fe on graphene can enhance the NO2 adsorption process. Adsorption energy calculations suggest that the enhancement in NO2 adsorption is more profound for Fe-doped mono- and tetra-vacant graphene than that for Fe doped bi- and tri-vacant graphene, which is favourable for NO2 gas capture applications. The unsaturated carbons in defected graphene as well as the oxygenated functional groups are very active to attract NO2 molecules. However, though the gas binding strength was not as high as the that found in the Fe-doped graphene structure, the relatively low NO2 gas adsorption energy is suitable for the practical gas sensors both for gas sensitivity and the sensor recovery rate factor. This theoretical study can potentially be useful for developing adsorption-based applications of graphene.

9.
Med J Armed Forces India ; 73(4): 375-379, 2017 Oct.
Article in English | MEDLINE | ID: mdl-29386713

ABSTRACT

BACKGROUND: Tungiasis is an ectoparasitosis caused by the sand flea Tunga penetrans. It is endemic in the under privileged communities of Latin America, the Caribbean and Sub Saharan Africa with geographic and seasonal variations even within endemic areas. We describe investigation of an outbreak of Tungiasis in troops deployed as part of UN peacekeeping force in Central Africa. METHODS: Tungiasis was diagnosed in an unusually large number of cases of severely pruritic boils over feet in soldiers of a UN peacekeeping battalion. An outbreak investigation was carried out and the outbreak was described in time, place and person distribution. A retrospective cohort study was done to ascertain the associated risk factors. RESULTS: A total of 36 cases were identified of which 33 had laboratory confirmation. Of the 36 cases, 10(27.77%) had only Fortaleza Stage II lesions, 22 (61.11%) a combination of Fortaleza Stage II and III lesions and four (11.11%) cases had a combination of Stage, II, III and IV lesions. Secondary bacterial infection was seen in 25 (69.44%) cases. Epidemiological analysis revealed that it was a common source single exposure outbreak traced to a temporary campsite along one of the patrolling routes. CONCLUSION: In a Military setting an integrated approach combining health education and environmental control is required to prevent such outbreaks.

10.
Oral Dis ; 22(5): 365-82, 2016 Jul.
Article in English | MEDLINE | ID: mdl-26602059

ABSTRACT

The aim of this paper was to perform a systematic review of the pathogenesis of medication-induced salivary gland dysfunction (MISGD). Review of the identified papers was based on the standards regarding the methodology for systematic reviews set forth by the World Workshop on Oral Medicine IV and the PRISMA statement. Eligible papers were assessed for both the degree and strength of relevance to the pathogenesis of MISGD as well as on the appropriateness of the study design and sample size. A total of 99 papers were retained for the final analysis. MISGD in human studies was generally reported as xerostomia (the sensation of oral dryness) without measurements of salivary secretion rate. Medications may act on the central nervous system (CNS) and/or at the neuroglandular junction on muscarinic, α-and ß-adrenergic receptors and certain peptidergic receptors. The types of medications that were most commonly implicated for inducing salivary gland dysfunction were those acting on the nervous, cardiovascular, genitourinary, musculoskeletal, respiratory, and alimentary systems. Although many medications may affect the salivary flow rate and composition, most of the studies considered only xerostomia. Thus, further human studies are necessary to improve our understanding of the association between MISGD and the underlying pathophysiology.


Subject(s)
Salivary Gland Diseases/chemically induced , Salivary Glands/drug effects , Drug-Related Side Effects and Adverse Reactions , Humans , Oral Medicine/methods , Salivary Gland Diseases/pathology , Salivary Glands/pathology
11.
Arch Oral Biol ; 60(6): 863-74, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25841068

ABSTRACT

This narrative review of the functions of saliva was conducted in the PubMed, Embase and Web of Science databases. Additional references relevant to the topic were used, as our key words did not generate references which covered all known functions of saliva. These functions include maintaining a moist oral mucosa which is less susceptible to abrasion, and removal of micro-organisms, desquamated epithelial cells, leucocytes and food debris by swallowing. The mucins form a slimy coating on all surfaces in the mouth and act as a lubricant during such processes as mastication, formation of a food bolus, swallowing and speaking. Saliva provides the fluid in which solid tastants may dissolve and distributes tastants around the mouth to the locations of the taste buds. The hypotonic unstimulated saliva facilitates taste recognition. Salivary amylase is involved in digestion of starches. Saliva acts as a buffer to protect oral, pharyngeal and oesophageal mucosae from orally ingested acid or acid regurgitated from the stomach. Saliva protects the teeth against acid by contributing to the acquired enamel pellicle, which forms a renewable lubricant between opposing tooth surfaces, by being supersaturated with respect to tooth mineral, by containing bicarbonate as a buffer and urea and by facilitating clearance of acidic materials from the mouth. Saliva contains many antibacterial, antiviral and antifungal agents which modulate the oral microbial flora in different ways. Saliva also facilitates the healing of oral wounds. Clearly, saliva has many functions which are needed for proper protection and functioning of the human body.


Subject(s)
Saliva/physiology , Cariogenic Agents , Humans , Lubrication , Mouth Mucosa/physiology , Olfactory Perception/physiology , Saliva/chemistry , Saliva/metabolism , Salivary Proteins and Peptides/physiology , Secretory Rate , Taste Perception/physiology , Tooth Diseases/prevention & control , Wound Healing/physiology
12.
Med J Armed Forces India ; 70(3): 225-9, 2014 Jul.
Article in English | MEDLINE | ID: mdl-25378774

ABSTRACT

BACKGROUND: Various Serosurveys and studies provide ample evidence of differing perspectives regarding epidemiology of HAV and HEV in India. This study was conducted to assess the seroprevalence of HAV and HEV and its associated factors with an aim to provide inputs to planners regarding requirement of HAV vaccine. METHODS: A multi-centric cross sectional survey amongst 4175 healthy trainees (young adults) was carried out in training centres, selected by multistage random sampling, giving equal representation to all regions of India. Sample size was calculated by taking prevalence of HAV seropositivity amongst adults as 60% and alpha 0.05. RESULTS: Seroprevalence for HAV and HEV was 92.68% (95% CI 91.82, 93.47) and 17.05% (15.90, 18.26), respectively. Logistic regression showed that hand washing without soap, regular close contact with domestic animals, consumption of unpasteurized milk and regular consumption of food outside home were risk factors for HAV (p < 0.05). For HEV, irregular hand washing, consumption of unpasteurized milk and irregular consumption of freshly prepared food were risk factors (p < 0.05). CONCLUSION: High level of immunity against HAV among the healthy young adults clearly demonstrates that vaccination against HAV is not required at present in our country. The large proportion being susceptible to HEV points towards the requirement of preventive strategies in the form of safe drinking water supply, hygiene, sanitation, increasing awareness and behaviour change with respect to personal hygiene especially hand and food hygiene.

13.
Nat Prod Res ; 28(20): 1680-4, 2014.
Article in English | MEDLINE | ID: mdl-25022439

ABSTRACT

Essential oils from odorous and volatile compounds possessing several therapeutic benefits are considered of a paramount importance in everyday human life. This study deals with a comparative study of essential oils from different parts of an aromatic plant Kundmannia sicula (L.) DC. (Apiaceae) growing in Tunisia. The hydro-distilled essential oils of the leaves and inflorescences with mature seeds (IMS) of K. sicula were analysed for the first time by gas chromatography equipped with flame ionisation detector and gas chromatography coupled with mass spectrometry. Fifty leaves and 47 IMS constituents were identified, accounting for 97.9% and 98.2% of the total oil, respectively. The major compounds identified from the leaves and IMS oils were isocurcumenol (9.9-10.1%), hexadecanoic acid (9.5-10.9%), spathulenol (6.9-3.4%), 10-epi-γ-eudesmol (6.3-5.5%), α-cubebene (5.9-6.1%) and trans-dihydro occidentalol (52-6.6%). The essential oil consists mainly of oxygenated monoterpenes (50.7-53.2%).


Subject(s)
Apiaceae/chemistry , Monoterpenes/chemistry , Oils, Volatile/chemistry , Flowers/chemistry , Plant Leaves/chemistry , Sesquiterpenes/chemistry , Tunisia
14.
Science ; 343(6172): 752-4, 2014 Feb 14.
Article in English | MEDLINE | ID: mdl-24531966

ABSTRACT

Graphene-based materials can have well-defined nanometer pores and can exhibit low frictional water flow inside them, making their properties of interest for filtration and separation. We investigate permeation through micrometer-thick laminates prepared by means of vacuum filtration of graphene oxide suspensions. The laminates are vacuum-tight in the dry state but, if immersed in water, act as molecular sieves, blocking all solutes with hydrated radii larger than 4.5 angstroms. Smaller ions permeate through the membranes at rates thousands of times faster than what is expected for simple diffusion. We believe that this behavior is caused by a network of nanocapillaries that open up in the hydrated state and accept only species that fit in. The anomalously fast permeation is attributed to a capillary-like high pressure acting on ions inside graphene capillaries.

15.
Indian J Pharm Sci ; 75(4): 457-62, 2013 Jul.
Article in English | MEDLINE | ID: mdl-24302801

ABSTRACT

The essential oils of the flowering aerial parts of two Ocimum species viz., Ocimum gratissimum and O. sanctum were analyzed by gas chromatography and gas chromatography/mass spectroscopy. The principal constituent of O. gratissimum and O. sanctum was eugenol (75.1%) and methyl eugenol (92.4%), comprising 99.3 and 98.9% of the total oils, respectively. In vitro antimicrobial activity of the essential oils of O. gratissimum, O. sanctum and their major compounds eugenol and methyl eugenol were screened by using tube dilution methods. O. gratissimum oil was found highly active against S. marcescens while O. sanctum oil showed significant activity against A. niger and S. faecalis. Methyl eugenol exhibited significant activity against P. aeruginosa while eugenol was effective only against S. aureus. Antioxidant activity of oils, eugenol, and methyl eugenol was determined by 2,2-diphenyl-1-picrylhydrazyl and 2,2'- azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) assays. Essential oil of O. gratissimum showed comparative antioxidant activity with IC50 values 23.66±0.55 and 23.91±0.49 µg/ml in 2,2-diphenyl-1-picrylhydrazyl and 2,2'- azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) models, respectively. Eugenol showed slightly weaker antioxidant activity compared to oil of O. gratissimum, while O. sanctum oil demonstrated very feeble antioxidant activity and methyl eugenol did not show any activity. Eugenol and methyl eugenol would be elite source from O. gratissimum and O. sanctum, respectively, of this region could be consider as a source of natural food antioxidant, preservatives, and as an antiseptic.

16.
Genet Mol Res ; 10(4): 2637-52, 2011 Oct 25.
Article in English | MEDLINE | ID: mdl-22057959

ABSTRACT

Pathogen infection in plants is often limited by a multifaceted defense response triggered by resistance genes. The most prevalent class of resistance proteins includes those that contain a nucleotide-binding site-leucine-rich repeat (NBS-LRR) domain. Over the past 15 years, more than 50 novel NBS-LRR class resistance genes have been isolated and characterized; they play a significant role in activating conserved defense-signaling networks. Recent molecular research on NBS-LRR resistance proteins and their signaling networks has the potential to broaden the use of resistance genes for disease control. Various transgenic approaches have been tested to broaden the disease resistance spectrum using NBS-LRR genes. This review highlights the recent progress in understanding the structure, function, signal transduction ability of NBS-LRR resistance genes in different host-pathogen systems and suggests new strategies for engineering pathogen resistance in crop plants.


Subject(s)
Genes, Plant/physiology , Host-Pathogen Interactions/genetics , Plant Diseases/genetics , Plant Proteins/genetics , Plants/genetics , Signal Transduction/genetics , Plants/microbiology
17.
Genet Mol Res ; 9(3): 1796-806, 2010 Sep 08.
Article in English | MEDLINE | ID: mdl-20830672

ABSTRACT

Turmeric (Curcuma longa), an important asexually reproducing spice crop of the family Zingiberaceae is highly susceptible to bacterial and fungal pathogens. The identification of resistance gene analogs holds great promise for development of resistant turmeric cultivars. Degenerate primers designed based on known resistance genes (R-genes) were used in combinations to elucidate resistance gene analogs from Curcuma longa cultivar surama. The three primers resulted in amplicons with expected sizes of 450-600 bp. The nucleotide sequence of these amplicons was obtained through sequencing; their predicted amino acid sequences compared to each other and to the amino acid sequences of known R-genes revealed significant sequence similarity. The finding of conserved domains, viz., kinase-1a, kinase-2 and hydrophobic motif, provided evidence that the sequences belong to the NBS-LRR class gene family. The presence of tryptophan as the last residue of kinase-2 motif further qualified them to be in the non-TIR-NBS-LRR subfamily of resistance genes. A cluster analysis based on the neighbor-joining method was carried out using Curcuma NBS analogs together with several resistance gene analogs and known R-genes, which classified them into two distinct subclasses, corresponding to clades N3 and N4 of non-TIR-NBS sequences described in plants. The NBS analogs that we isolated can be used as guidelines to eventually isolate numerous R-genes in turmeric.


Subject(s)
Curcuma/metabolism , Plant Proteins/chemistry , Plant Proteins/genetics , Amino Acid Sequence , Curcuma/genetics , Curcuma/microbiology , Molecular Sequence Data , Phylogeny , Plant Diseases/genetics , Plant Diseases/microbiology , Plant Proteins/metabolism , Sequence Homology, Amino Acid
18.
J Ethnopharmacol ; 128(3): 703-4, 2010 Apr 21.
Article in English | MEDLINE | ID: mdl-20176098

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Craniotome furcata (Link.) O. Kuntze (Lamiaceae) is used in the traditional medicine for the treatment of cuts and wounds indicating antimicrobial activity. AIM OF THE STUDY: To validate the traditional medicinal claim, in vitro antimicrobial activity of the extracts was screened against eleven human pathogenic bacteria and fungi. MATERIALS AND METHODS: The ethyl acetate (CE) and n-butanol (CB) extracts of the aerial parts of Craniotome furcata were tested against four Gram-positive bacteria, four Gram-negative bacteria and three fungi species. Antimicrobial activity was determined by the tube-dilution method. RESULTS: The CE and CB extracts showed antimicrobial activity against all of the tested microorganisms, with minimum inhibitory concentration (MIC) values in the range of 0.41-4.58mg/ml. CONCLUSIONS: The tested microbes Micrococcus flavus and Escherichia coli were highly susceptible to extract CE and antimicrobial activity of CB is comparable to that of extract CE against Escherichia coli and Staphylococcus faecalis while it is better than that of extract CE, against Klebsiella pneumoniae. Both the extracts were found less susceptible against tested fungi.


Subject(s)
Anti-Infective Agents/pharmacology , Bacteria/drug effects , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Lamiaceae , 1-Butanol , Dosage Forms , Escherichia coli/drug effects , Ethnopharmacology , Fungi/drug effects , Humans , Medicine, Traditional , Microbial Sensitivity Tests
19.
J Nanosci Nanotechnol ; 7(6): 1930-4, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17654967

ABSTRACT

In2O3 nanoparticle layers having an average size of 8, 11, 15, 21, and 29 nm have been deposited using a two-step method consisting of chemical capping and dip coating techniques. The gas sensing properties in terms of sensor response and response time of the nanoparticle layers towards ethanol have been studied as a function of ethanol concentration and operating temperature. It has been observed that the sensor response increases and the response time decreases with decreasing size in the size range of 5-15 nm. The increase in sensor response at smaller nanoparticle size has been explained in terms of the increase in surface area and particle size becoming comparable to the electron Debye length.


Subject(s)
Biosensing Techniques/methods , Electrochemistry/methods , Gases/analysis , Indium/chemistry , Nanostructures/chemistry , Nanostructures/ultrastructure , Nanotechnology/methods , Crystallization/methods , Gases/chemistry , Macromolecular Substances/chemistry , Materials Testing , Molecular Conformation , Particle Size , Sensitivity and Specificity , Surface Properties
20.
Glycobiology ; 11(5): 423-32, 2001 May.
Article in English | MEDLINE | ID: mdl-11425803

ABSTRACT

Among alpha 3-fucosyltransferases (alpha3-FucTs) from most species, four cysteine residues appear to be highly conserved. Two of these cysteines are located at the N-terminus and two at the C-terminus of the catalytic domain. FucT VII possesses two additional cysteines in close proximity to each other located in the middle of the catalytic domain. We identified the disulfide bridges in a recombinant, soluble form of human FucT VII. Potential free cysteines were modified with a biotinylated alkylating reagent, disulfide bonds were reduced and alkylated with iodoacetamide, and the protein was digested with either trypsin or chymotrypsin, before characterization by high-performance liquid chromatography/electrospray ionization mass spectrometry. More than 98% of the amino acid sequence for the truncated enzyme (beginning at amino acid 53) was verified. Mass spectrometry analysis also demonstrated that both potential N-linked sites are occupied. All six cysteines in the FucT VII sequence were shown to be disulfide-linked. The pairing of the cysteines was determined by proteolytic cleavage of nonreduced protein and subsequent analysis by mass spectrometry. The results demonstrated that Cys(68)-Cys(76), Cys(211)-Cys(214), and Cys(318)-Cys(321) are disulfide-linked. We have used this information, together with a method of fold recognition and homology modeling, using the (alpha/beta)(8)-barrel fold of Escherichia coli dihydrodipicolinate synthase as a template to propose a model for FucT VII.


Subject(s)
Fucosyltransferases/chemistry , Amino Acid Sequence , Cysteine/chemistry , Disulfides/chemistry , Fucosyltransferases/genetics , Glycosylation , Humans , Mass Spectrometry , Models, Molecular , Molecular Sequence Data , Protein Structure, Secondary , Recombinant Proteins/chemistry , Recombinant Proteins/genetics
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