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Protein D (protein + d)
Selected AbstractsCollectin structure: A reviewPROTEIN SCIENCE, Issue 9 2000Kjell Håkansson Abstract Colleetins are animal calcium dependent lectins that target the carbohydrate structures on invading pathogens, resulting in the agglutination and enhanced clearance of the microorganism. These proteins form trimers that may assemble into larger oligomers. Each polypeptide chain consists of four regions: a relatively short N-terminal region, a collagen like region, an ,-helical coiled-coil, and the lectin domain. Only primary structure data are available for the N-terminal region, while the most important features of the collagen-like region can be derived from its homology with collagen. The structures of the ,-helical coiled-coil and the lectin domain are known from crystallographic studies of mannan binding protein (MBP) and lung surfactant protein D (SP-D). Carbohydrate binding has been structurally characterized in several complexes between MBP and carbohydrate; all indicate that the major interaction between carbohydrate and collectin is the binding of two adjacent carbohydrate hydroxyl group to a collectin calcium ion. In addition, these hydroxyl groups hydrogen bond to some of the calcium amino acid ligands. While each collectin trimer contains three such carbohydrate binding sites, deviation from the overall threefold symmetry has been demonstrated for SP-D, which may influence its binding properties. The protein surface between the three binding sites is positively charged in both MBP and SP-D. [source] Delayed Lung Maturation of Foetus of Diabetic Mother Rats Develop with a Diminish, but Without Changes in the Proportion of Type I and II Pneumocytes, and Decreased Expression of Protein D-Associated Surfactant FactorANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2009M. Treviño-Alanís Summary Newborn children of diabetic mothers have an increased morbidity and mortality because of respiratory distress syndrome. We study lung histogenesis during intrauterine development of offspring of diabetic Sprague-Dawley rats at 18, 19 and 21 days of gestation (DG). Pregnant rats were grouped into diabetic (streptozotocin-induced), citrate, and control groups; five female and five male offspring were selected randomly from each group at 18, 19 and 21 DG, and a biopsy of the lung was taken and processed in paraffin for histological examination. The biopsy for the transmission electron microscopy (TEM) analysis was taken at 21 days. A delay in alveolization of the offspring at 18, 19 and 21 days of the diabetic group was observed, which was confirmed at TEM level, and also less quantity of protein D associated to surfactant in diabetic group was detected (P < 0.001). The foetuses of the diabetic group presented a delay in lung histogenesis and in differentiation of the type II pneumocytes cells, but conserved the proportion with a decrease in 50% of pneumocytes, accompanied by a diminish of protein D associated to surfactant factor. [source] The genes encoding bovine SP-A, SP-D, MBL-A, conglutinin, CL-43 and CL-46 form a distinct collectin locus on Bos taurus chromosome 28 (BTA28) at position q.1.8,1.9ANIMAL GENETICS, Issue 4 2004M. Gjerstorff Summary Collectins are a group of C-type lectins involved in the innate immune system, where they mediate and modulate clearance of pathogens. The health status of cattle is of major economical and ethical concern; therefore, the study of bovine collectins is of importance. The collectins conglutinin, CL-43 and CL-46 are only present in Bovidae and the characterization of their genes indicates that they are structural descendants of another collectin, lung surfactant protein D (SP-D). In this study, we assembled BAC clones into a contig spanning 330,1150 kb, which includes the bovine genes encoding the collectins SP-A (SFTPA), SP-D (SFTPD), mannan-binding lectin A (MBL1), CL-43 (COLEC9), CL-46 (COLEC13) and conglutinin (COLEC8). In the same contig, we also identified a gene that potentially encodes a novel conglutinin-like collectin (COLEC14). The arrangement of STFPA, SFTPD and MBL1 is homologous to the organization found in humans and mice, whereas the Bovidae-specific collectin genes, COLEC8, COLEC9 and COLEC13, extend from SFTPD. Proximal to the collectin locus at BTA28q1.8,1.9, and included in the contig, we found the microsatellite IDVGA8, which may be a valuable marker for tracking polymorphisms in the linked collectin genes. [source] Crystallization and preliminary crystallographic characterization of the iron-regulated outer membrane lipoprotein FrpD from Neisseria meningitidisACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 9 2010Ekaterina Sviridova Fe-regulated protein D (FrpD) is a Neisseria meningitidis outer membrane lipoprotein that may be involved in the anchoring of the secreted repeat in toxins (RTX) protein FrpC to the outer bacterial membrane. However, the function and biological roles of the FrpD and FrpC proteins remain unknown. Native and selenomethionine-substituted variants of recombinant FrpD43,271 protein were crystallized using the sitting-drop vapour-diffusion method. Diffraction data were collected to a resolution of 2.25,Å for native FrpD43,271 protein and to a resolution of 2.00,Å for selenomethionine-substituted FrpD43,271 (SeMet FrpD43,271) protein. The crystals of native FrpD43,271 protein belonged to the hexagonal space group P62 or P64, while the crystals of SeMet FrpD43,271 protein belonged to the primitive orthorhombic space group P212121. [source] Autosomal Dominant Adult Neuronal Ceroid Lipofuscinosis: a Novel Form of NCL with Granular Osmiophilic Deposits without Palmitoyl Protein Thioesterase 1 DeficiencyBRAIN PATHOLOGY, Issue 4 2003Peter C. G. Nijssen We describe the neuropathological and biochemical autopsy findings in 3 patients with autosomal dominant adult neuronal ceroid lipofuscinosis (ANCL, Parry type; MIM 162350), from a family with 6 affected individuals in 3 generations. Throughout the brain of these patients, there was abundant intraneuronal lysosomal storage of autofluorescent lipopigment granules. Striking loss of neurons in the substantia nigra was found. In contrast, little neuronal cell loss occurred in other cerebral areas, despite massive neuronal inclusions. Visceral storage was present in gut, liver, cardiomyocytes, skeletal muscle, and in the skin eccrine glands. The storage material showed highly variable immunoreactivity with antiserum against subunit c of mitochondrial ATP synthase, but uniform strong immunoreactivity for saposin D (sphingolipid activating protein D). Protein electrophoresis of isolated storage material revealed a major protein band of about 14 kDa, recognized in Western blotting by saposin D antiserum (but not subunit c of mitochondrial ATPase (SCMAS) antiserum). Electron microscopy showed ample intraneuronal granular osmiophilic deposits (GRODs), as occurs in CLN1 and congenital ovine NCL. These forms of NCL are caused by the deficiencies of palmitoyl protein thioesterase 1 and cathepsin D, respectively. However, activities of these enzymes were within normal range in our patients. Thus we propose that a gene distinct from the cathepsin D and CLN1-CLN8 genes is responsible for this autosomal dominant form of ANCL. [source] SP-D and regulation of the pulmonary innate immune system in allergic airway changesCLINICAL & EXPERIMENTAL ALLERGY, Issue 4 2010L. R. Forbes Summary The airway mucosal surfaces are constantly exposed to inhaled particles that can be potentially toxic, infectious or allergenic and should elicit inflammatory changes. The proximal and distal air spaces, however, are normally infection and inflammation free due to a specialized interplay between cellular and molecular components of the pulmonary innate immune system. Surfactant protein D (SP-D) is an epithelial-cell-derived immune modulator that belongs to the small family of structurally related Ca2+ -dependent C-type collagen-like lectins. While collectins can be detected in mucosal surfaces of various organs, SP-A and SP-D (the ,lung collectins') are constitutively expressed in the lung at high concentrations. Both proteins are considered important players of the pulmonary immune responses. Under normal conditions however, SP-A-/- mice display no pathological features in the lung. SP-D-/- mice, on the other hand, show chronic inflammatory alterations indicating a special importance of this molecule in regulating immune homeostasis and the function of the innate immune cells. Recent studies in our laboratory and others implied significant associations between changes in SP-D levels and the presence of airway inflammation both in animal models and patients raising a potential usefulness of this molecule as a disease biomarker. Research on wild-type and mutant recombinant molecules in vivo and in vitro showed that SP-D binds carbohydrates, lipids and nucleic acids with a broad spectrum specificity and initiates phagocytosis of inhaled pathogens as well as apoptotic cells. Investigations on gene-deficient and conditional over expressor mice in addition, provided evidence that SP-D directly modulates macrophage and dendritic cell function as well as T cell-dependent inflammatory events. Thus, SP-D has a unique, dual functional capacity to induce pathogen elimination on the one hand and control of pro-inflammatory mechanisms on the other, suggesting a potential suitability for therapeutic prevention and treatment of chronic airway inflammation without compromising the host defence function of the airways. This paper will review recent findings on the mechanisms of immune-protective function of SP-D in the lung. Cite this as: L. R. Forbes and A. Haczku, Clinical & Experimental Allergy, 2010 (40) 547,562. [source] Surfactant protein D inhibits mite-induced alveolar macrophage and dendritic cell activations through TLR signalling and DC-SIGN expressionCLINICAL & EXPERIMENTAL ALLERGY, Issue 1 2010C-F Liu Summary Background Surfactant protein D (SP-D), a secreted pattern recognition molecule associated with pulmonary innate immunity, has been shown to mediate the clearance of pathogens in multiple ways. However, how SP-D interacts with alveolar macrophages (AMs) and dendritic cells (DCs) during allergen exposure remains unclear. Objective This study was performed to characterize the immunomodulatory effects of SP-D on mite allergen (Dermatophagoides pteronyssinus, Der p)-induced inflammatory signalling in AMs and DCs. Methods Murine AM, alveolar macrophage cell line derived from BALB/c mice (MH-S cells), and human monocyte-derived dendritic cells (MDDC) were used as model systems. The production of nitric oxide (NO) and TNF-,, expression of surface Toll-like receptors (TLRs), and expression of the C-type lectin receptor known as dendritic cell (DC)-specific ICAM-grabbing non-integrin (DC-SIGN) were measured as a function of pretreatment with SP-D and subsequent exposure to Der p. Der p-dependent cellular activations that were modified by SP-D in these model systems were then identified. Results Pretreatment of MH-S cells with SP-D reduced Der p-dependent production of NO, TNF-,, and the downstream activations of IL-1 receptor-associated kinase, mitogen activated protein kinase (MAPK) kinase, and nuclear factor-,B. SP-D interacted with CD14 such that CD14 binding to Der p was inhibited and Der p-induced signalling via TLRs was blocked. DC-SIGN expression was suppressed by Der p in MH-S and MDDC; this down-regulation of DC-SIGN expression was prevented by pretreatment with SP-D. Conclusions These results indicated that the inhibition of Der p-induced activation of MH-S and MDDC by SP-D is mediated through suppression of the CD14/TLR signalling pathway and maintenance of DC-SIGN expression, which may protect allergen-induced airway inflammation. Cite this as: C-F Liu, M. Rivere, H-J Huang, G. Puzo and J-Y Wang, Clinical & Experimental Allergy, 2010 (40) 111,122. [source] Surfactant protein D and asthmaCLINICAL & EXPERIMENTAL ALLERGY, Issue 12 2004A. Haczku First page of article [source] Development of a membrane-assisted hybrid bioreactor for ammonia and COD removal in wastewatersJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2 2005Vinka Oyanedel Abstract A new membrane-assisted hybrid bioreactor was developed to remove ammonia and organic matter. This system was composed of a hybrid circulating bed reactor (CBR) coupled in series to an ultrafiltration membrane module for biomass separation. The growth of biomass both in suspension and biofilms was promoted in the hybrid reactor. The system was operated for 103 days, during which a constant ammonia loading rate (ALR) was fed to the system. The COD/N-NH4+ ratio was manipulated between 0 and 4, in order to study the effects of different organic matter concentrations on the nitrification capacity of the system. Experimental results have shown that it was feasible to operate with a membrane hybrid system attaining 99% chemical oxygen demand (COD) removal and ammonia conversion. The ALR was 0.92 kg N-NH4+ m,3 d,1 and the organic loading rate (OLR) achieved up to 3.6 kg COD m,3 d,1. Also, the concentration of ammonia in the effluent was low, 1 mg N-NH4+ dm,3. Specific activity determinations have shown that there was a certain degree of segregation of nitrifiers and heterotrophs between the two biomass phases in the system. Growth of the slow-growing nitrifiers took place preferentially in the biofilm and the fast-growing heterotrophs grew in suspension. This fact allowed the nitrifying activity in the biofilm be maintained around 0.8 g N g,1 protein d,1, regardless of the addition of organic matter in the influent. The specific nitrifying activity of suspended biomass varied between 0.3 and 0.4 g N g,1 VSS d,1. Copyright © 2004 Society of Chemical Industry [source] | ||||||||||||||||