scholarly journals Interaction of SP-A (surfactant protein A) with bacterial rough lipopolysaccharide (Re-LPS), and effects of SP-A on the binding of Re-LPS to CD14 and LPS-binding protein

2005 ◽  
Vol 391 (1) ◽  
pp. 115-124 ◽  
Author(s):  
Ignacio García-Verdugo ◽  
Fernando Sánchez-Barbero ◽  
Katrin Soldau ◽  
Peter S. Tobias ◽  
Cristina Casals
Keyword(s):  
Binding Protein ◽  
Protein A ◽  
Fluorescence Analysis ◽  
Surfactant Protein ◽  
Lipid Binding ◽  
Coli Strain ◽  
Surfactant Protein A ◽  
Human Macrophage ◽  
Independent Manner ◽  
Lps Binding

SP-A (surfactant protein A) is a lipid-binding collectin primarily involved in innate lung immunity. SP-A interacts with the bacterial rough LPS (lipopolysaccharide) Re-LPS (Re595 mutant of LPS from Salmonella minnesota), but not with smooth LPS. In the present study, we first examined the characteristics of the interaction of human SP-A with Re-LPS. Fluorescence intensity and anisotropy measurements of FITC-labelled Re-LPS in the presence and absence of SP-A indicated that SP-A bound to Re-LPS in solution in a Ca2+-independent manner, with a dissociation constant of 2.8×10−8 M. In the presence of calcium, a high-mobility complex of SP-A and [3H]Rb-LPS (Rb mutant of LPS from Escherichia coli strain LCD 25) micelles was formed, as detected by sucrose density gradients. Re-LPS aggregation induced by SP-A was further characterized by light scattering. On the other hand, human SP-A inhibited TNF-α (tumour necrosis factor-α) secretion by human macrophage-like U937 cells stimulated with either Re-LPS or smooth LPS. We further examined the effects of human SP-A on the binding of Re-LPS to LBP (LPS-binding protein) and CD14. SP-A decreased the binding of Re-LPS to CD14, but not to LBP, as detected by cross-linking experiments with 125I-ASD-Re-LPS [125I-labelled sulphosuccinimidyl-2-(p-azidosalicylamido)-1,3-dithiopropionate derivative of Re-LPS] and fluorescence analysis with FITC-Re-LPS. When SP-A, LBP and CD14 were incubated together, SP-A reduced the ability of LBP to transfer 125I-ASD-Re-LPS to CD14. These SP-A effects were not due to the ability of SP-A to aggregate Re-LPS in the presence of calcium, since they were observed in both the absence and the presence of calcium. These studies suggest that SP-A could contribute to modulate Re-LPS responses by altering the competence of the LBP–CD14 receptor complex.

Introduction of Mannose Binding Protein-Type Phosphatidylinositol Recognition into Pulmonary Surfactant Protein A†

Biochemistry ◽  
1999 ◽  
Vol 38 (22) ◽  
pp. 7321-7331 ◽  
Author(s):  
Hirofumi Chiba ◽  
Hitomi Sano ◽  
Masaki Saitoh ◽  
Hitoshi Sohma ◽  
Dennis R. Voelker ◽  
...  
Keyword(s):  
Pulmonary Surfactant ◽  
Binding Protein ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Mannose Binding Protein ◽  
Mannose Binding ◽  
Pulmonary Surfactant Protein

Identification and characterization of p63 (CKAP4/ERGIC-63/CLIMP-63), a surfactant protein A binding protein, on type II pneumocytes

2006 ◽  
Vol 291 (3) ◽  
pp. L436-L446 ◽  
Author(s):  
Nisha Gupta ◽  
Yefim Manevich ◽  
Altaf S. Kazi ◽  
Jian-Qin Tao ◽  
Aron B. Fisher ◽  
...  
Keyword(s):  
Binding Protein ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Type Ii Cells ◽  
Receptor Complex ◽  
Type Ii ◽  
Surface Binding ◽  
Intact Mouse ◽  
The Cross

Surfactant protein A (SP-A) binds to alveolar type II cells through a specific high-affinity cell membrane receptor, although the molecular nature of this receptor is unclear. In the present study, we have identified and characterized an SP-A cell surface binding protein by utilizing two chemical cross-linkers: profound sulfo-SBED protein-protein interaction reagent and dithiobis(succinimidylpropionate) (DSP). Sulfo-SBED-biotinylated SP-A was cross-linked to the plasma membranes isolated from rat type II cells, and the biotin label was transferred from SP-A to its receptor by reduction. The biotinylated SP-A-binding protein was identified on blots by using streptavidin-labeled horseradish peroxidase. By using DSP, we cross-linked SP-A to intact mouse type II cells and immunoprecipitated the SP-A-receptor complex using anti-SP-A antibody. Both of the cross-linking approaches showed a major band of 63 kDa under reduced conditions that was identified as the rat homolog of the human type II transmembrane protein p63 (CKAP4/ERGIC-63/CLIMP-63) by matrix-assisted laser desorption ionization and nanoelectrospray tandem mass spectrometry of tryptic fragments. Thereafter, we confirmed the presence of p63 protein in the cross-linked SP-A-receptor complex by immunoprobing with p63 antibody. Coimmunoprecipitation experiments and functional assays confirmed specific interaction between SP-A and p63. Antibody to p63 could block SP-A-mediated inhibition of ATP-stimulated phospholipid secretion. Both intracellular and membrane localized pools of p63 were detected on type II cells by immunofluorescence and immunobloting. p63 colocalized with SP-A in early endosomes. Thus p63 closely interacts with SP-A and may play a role in the trafficking or the biological function of the surfactant protein.

scholarly journals Elucidation of Lipid Binding Sites on Lung Surfactant Protein A Using X-ray Crystallography, Mutagenesis, and Molecular Dynamics Simulations

Biochemistry ◽  
2016 ◽  
Vol 55 (26) ◽  
pp. 3692-3701 ◽  
Author(s):  
Boon Chong Goh ◽  
Huixing Wu ◽  
Michael J. Rynkiewicz ◽  
Klaus Schulten ◽  
Barbara A. Seaton ◽  
...  
Keyword(s):  
Binding Sites ◽  
Lung Surfactant ◽  
Protein A ◽  
Surfactant Protein ◽  
Lipid Binding ◽  
Surfactant Protein A ◽  
X Ray ◽  
X Ray Crystallography ◽  
Lung Surfactant Protein ◽  
Dynamics Simulations

Surfactant protein A inhibits alveolar macrophage cytokine production by CD14-independent pathway

2004 ◽  
Vol 286 (1) ◽  
pp. L129-L136 ◽  
Author(s):  
John F. Alcorn ◽  
Jo Rae Wright
Keyword(s):  
Alveolar Macrophages ◽  
Cytokine Production ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Null Mouse ◽  
Mrna Levels ◽  
Wild Type ◽  
Independent Manner ◽  
Tnf Α

The lung collectin surfactant protein A (SP-A) has both anti-inflammatory and prophagocytic activities. We and others previously showed that SP-A inhibits the macrophage production of tumor necrosis factor (TNF)-α stimulated by the gram-negative bacterial component LPS. We propose that SP-A decreases the production of proinflammatory cytokines by alveolar macrophages via a CD14-independent mechanism. SP-A inhibited LPS-simulated TNF-α production in rat and mouse macrophages in the presence and absence of serum (72% and 42% inhibition, respectively). In addition, SP-A inhibited LPS-induced mRNA levels for TNF-α, IL-1α, and IL-1β as well as NF-κB DNA binding activity. SP-A also diminished ultrapure LPS-stimulated TNF-α produced by wild-type and CD14-null mouse alveolar macrophages by 58% and 88%, respectively. Additionally, SP-A inhibited TNF-α stimulated by PMA in both wild-type and TLR4-mutant macrophages. These data suggest that SP-A inhibits inflammatory cytokine production in a CD14-independent manner and also by mechanisms independent of the LPS signaling pathway.

scholarly journals Identification and Characterization of Human Surfactant Protein A Binding Protein of Mycoplasma pneumoniae

2005 ◽  
Vol 73 (5) ◽  
pp. 2828-2834 ◽  
Author(s):  
T. R. Kannan ◽  
D. Provenzano ◽  
J. R. Wright ◽  
J. B. Baseman
Keyword(s):  
Amino Acids ◽  
Mycoplasma Pneumoniae ◽  
Pertussis Toxin ◽  
Binding Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Dependent Manner ◽  
Extracellular Matrix Components

ABSTRACT Mycoplasma pneumoniae infections represent a major primary cause of human respiratory diseases, exacerbate other respiratory disorders, and are associated with extrapulmonary pathologies. Cytadherence is a critical step in mycoplasma colonization, aided by a network of mycoplasma adhesins and cytadherence accessory proteins which mediate binding to host cell receptors. Furthermore, the respiratory mucosa is enriched with extracellular matrix components, including surfactant proteins, fibronectin, and mucin, which provide additional in vivo targets for mycoplasma parasitism. In this study we describe interactions between M. pneumoniae and human surfactant protein-A (hSP-A). Initially, we found that viable M. pneumoniae cells bound to immobilized hSP-A in a dose- and calcium (Ca2+)-dependent manner. Mild trypsin treatment of intact mycoplasmas reduced binding markedly (80 to 90%) implicating a surface-associated mycoplasma protein(s). Using hSP-A-coupled Sepharose affinity chromatography and polyacrylamide gel electrophoresis, we identified a 65-kDa hSP-A binding protein of M. pneumoniae. The presence of Ca2+ enhanced binding of the 65-kDa protein to hSP-A, which was reduced by the divalent cation-chelating agent, EDTA. The 65-kDa hSP-A binding protein of M. pneumoniae was identified by sequence analysis as a novel protein (MPN372) possessing a putative S1-like subunit of pertussis toxin at the amino terminus (amino acids 1 to 226), with the remaining amino acids (227 to 591) exhibiting no homology with other subunits of pertussis toxin, other known toxins, or any reported proteins. Recombinant MPN372 (MPN372) bound to hSP-A in a dose-dependent manner, which was markedly reduced by preincubation with mouse recombinant MPN372 antisera. Also, adherence of viable M. pneumoniae cells to hSP-A was inhibited by recombinant MPN372 antisera, demonstrating that MPN372, a previously designated hypothetical protein, is surface exposed and mediates mycoplasma attachment to hSP-A.

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