scholarly journals Structural characteristics and intermolecular organization of human pulmonary-surfactant-associated proteins

1986 ◽  
Vol 240 (1) ◽  
pp. 107-114 ◽  
Author(s):  
S W Crawford ◽  
R P Mecham ◽  
H Sage
Keyword(s):  
Pulmonary Surfactant ◽  
Peptide Mapping ◽  
Structural Characteristics ◽  
Three Dimensional ◽  
Lavage Fluid ◽  
Clinical Syndrome ◽  
Structural Relationships ◽  
Associated Proteins ◽  
Cross Links ◽  
Covalently Linked

The structural relationships and intermolecular organization among the proteins associated with pulmonary surfactant are largely unknown. We studied the pulmonary-surfactant-associated proteins in the bronchoalveolar lavage fluid obtained from a patient with the clinical syndrome of alveolar proteinosis. The major proteins with Mr values of 32,000-36,000 and 62,000 formed thiol-dependent complexes (Mr greater than 400,000) with intermolecular disulphide bonds present in the collgenase-sensitive domains of these proteins. In contrast, other proteins, which were collagenase-insensitive, formed thiol-dependent oligomers that were not covalently linked to the major proteins. The associations of these proteins in the surfactant of a normal individual were similar. By amino acid analysis, two-dimensional peptide mapping and bacterial-collagenase digestion the 32,000-36,000-Mr and 62,000-Mr proteins were nearly identical. Differences in CNBr cleavage products suggested that the larger of the proteins was formed by non-disulphide, covalent, cross-links in the collagenase-sensitive domains of the 32,000-36,000-Mr proteins. Thus the evidence suggested that the lipid-associated proteins of Mr 32,000-36, 000 contained both disulphide and non-disulphide cross-links in the collagen-like N-terminal region of the proteins and form higher-Mr complexes. This organization may support the three-dimensional conformation of surfactant in the alveolar space.

Pseudomonas aeruginosa protease IV degrades surfactant proteins and inhibits surfactant host defense and biophysical functions

2005 ◽  
Vol 288 (2) ◽  
pp. L409-L418 ◽  
Author(s):  
Jaret L. Malloy ◽  
Ruud A. W. Veldhuizen ◽  
Brett A. Thibodeaux ◽  
Richard J. O'Callaghan ◽  
Jo Rae Wright
Keyword(s):  
Surface Tension ◽  
Pseudomonas Aeruginosa ◽  
Host Defense ◽  
Pulmonary Surfactant ◽  
Lavage Fluid ◽  
Surfactant Proteins ◽  
Gel Chromatography ◽  
Respiratory Dysfunction ◽  
Associated Proteins ◽  
Protease Iv

Pulmonary surfactant has two distinct functions within the lung: reduction of surface tension at the air-liquid interface and participation in innate host defense. Both functions are dependent on surfactant-associated proteins. Pseudomonas aeruginosa is primarily responsible for respiratory dysfunction and death in cystic fibrosis patients and is also a leading pathogen in nosocomial pneumonia. P. aeruginosa secretes a number of proteases that contribute to its virulence. We hypothesized that P. aeruginosa protease IV degrades surfactant proteins and results in a reduction in pulmonary surfactant host defense and biophysical functions. Protease IV was isolated from cultured supernatant of P. aeruginosa by gel chromatography. Incubation of cell-free bronchoalveolar lavage fluid with protease IV resulted in degradation of surfactant proteins (SP)-A, -D, and -B. SPs were degraded in a time- and dose-dependent fashion by protease IV, and degradation was inhibited by the trypsin-like serine protease inhibitor Nα- p-tosyl-l-lysine-chloromethyl ketone (TLCK). Degradation by protease IV inhibited SP-A- and SP-D-mediated bacterial aggregation and uptake by macrophages. Surfactant treated with protease IV was unable to reduce surface tension as effectively as untreated surfactant, and this effect was inhibited by TLCK. We speculate that protease IV may be an important contributing factor to the development and propagation of acute lung injury associated with P. aeruginosa via loss of surfactant function within the lung.

Drawing of Piezoceramic Fibers and Ribbons Using a Novel Alginate Gelation Method and Properties of Fiber and Ribbon-Based Piezodevices

2012 ◽  
Vol 445 ◽  
pp. 380-385 ◽  
Author(s):  
Sedat Alkoy ◽  
A. Serkan Tekdas ◽  
Emre Tekel ◽  
Recep Olukkent
Keyword(s):  
Lead Zirconate Titanate ◽  
Piezoelectric Ceramic ◽  
Structural Characteristics ◽  
Slip Casting ◽  
Three Dimensional ◽  
Lead Zirconate ◽  
Ceramic Fibers ◽  
Dimensional Network ◽  
Dry Pressing ◽  
Cross Links

Piezoceramics are usually shaped into three dimensional bulk form using dry pressing or slip casting methods. However, certain applications require piezoceramics to be shaped in one dimensional fiber or two dimensional ribbon form. In this study, piezoceramic fibers and curved piezoceramic ribbons were fabricated using a novel alginate gelation method. Alginate is a natural linear polymer that is obtained from brown kelp. In the presence of multivalent cations, it forms ionic cross-links and gels in a three dimensional network form. In our study, gelation conditions of alginate containing aqueous slips of lead zirconate titanate based piezoelectric ceramic powders were investigated. Piezoelectric ceramic fibers and ceramic ribbons were prepared by sintering of gelled powders for transducer applications. Structural characteristics of these ceramics and electrical characteristics of piezodevices prepared from these ceramics were investigated and reported.

scholarly journals Can keratin scaffolds be used for creating three-dimensional cell cultures?

Open Medicine ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 249-253
Author(s):  
Marta Bochynska-Czyz ◽  
Patrycja Redkiewicz ◽  
Hanna Kozlowska ◽  
Joanna Matalinska ◽  
Marek Konop ◽  
...  
Keyword(s):  
Cell Cultures ◽  
Chemical Activation ◽  
Three Dimensional ◽  
Enzymatic Digestion ◽  
Pepsin Digestion ◽  
Cell Culturing ◽  
3D Cell Cultures ◽  
Associated Proteins ◽  
Positive Effect ◽  
Dimensional Cell

AbstractThree-dimensional (3D) cell cultures were created with the use of fur keratin associated proteins (F-KAPs) as scaffolds. The procedure of preparation F-KAP involves combinations of chemical activation and enzymatic digestion. The best result in porosity and heterogeneity of F-KAP surface was received during pepsin digestion. The F-KAP had a stable structure, no changes were observed after heat treatment, shaking and washing. The 0.15-0.5 mm fraction had positive effect for formation of 3D scaffolds and cell culturing. Living rat mesenchymal cells on the F-KAP with no abnormal morphology were observed by SEM during 32 days of cell culturing.

scholarly journals Hemp (Cannabis sativa L.) Seed Protein–EGCG Conjugates: Covalent Bonding and Functional Research

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1618
Author(s):  
Xin-Hui Pang ◽  
Yang Yang ◽  
Xin Bian ◽  
Bing Wang ◽  
Li-Kun Ren ◽  
...  
Keyword(s):  
Particle Size ◽  
Fluorescence Spectroscopy ◽  
Cannabis Sativa ◽  
Three Dimensional ◽  
Epigallocatechin Gallate ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Particle Size Data ◽  
Covalently Bonded ◽  
Covalently Linked

In order to make HPI have a wide application prospect in the food industry, we used EGCG to modify HPI. In this study, we prepared different concentrations (1, 2, 3, 4, and 5 mM) of (−)-epigallocatechin gallate (EGCG) covalently linked to HPI and use methods such as particle size analysis, circular dichroism (CD), and three-dimensional fluorescence spectroscopy to study the changes in the structure and functional properties of HPI after being covalently combined with EGCG. The particle size data indicated that the covalent HPI-EGCG complex was larger than native HPI, and the particle size was mainly distributed at about 200 μm. CD and three-dimensional fluorescence spectroscopy analyses showed that the conformation of the protein was changed by conjugation with EGCG. The β-sheet content decreased from 82.79% to 66.67% after EGCG bound to the protein, and the hydrophobic groups inside the protein were exposed, which increased the hydrophobicity of the protein and changed its conformation. After HPI and 1 mM of EGCG were covalently bonded, the solubility and emulsifying properties of the covalent complex were improved compared with native HPI. These results indicated that HPI-EGCG conjugates can be added in some foods.

scholarly journals Coupled Fluid–Solid Numerical Simulation for Flow Field Characteristics and Supporting Performance of Flexible Support Cylindrical Gas Film Seal

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 97
Author(s):  
Junfeng Sun ◽  
Meihong Liu ◽  
Zhen Xu ◽  
Taohong Liao ◽  
Xiangping Hu ◽  
...  
Keyword(s):  
Flow Field ◽  
Film Thickness ◽  
Fluid Dynamic ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
High Rotational Speed ◽  
Flexible Support ◽  
Flow Field Characteristics

A new type of cylindrical gas film seal (CGFS) with a flexible support is proposed according to the working characteristics of the fluid dynamic seal in high-rotational-speed fluid machinery, such as aero-engines and centrifuges. Compared with the CGFS without a flexible support, the CGFS with flexible support presents stronger radial floating characteristics since it absorbs vibration and reduces thermal deformation of the rotor system. Combined with the structural characteristics of a film seal, an analytical model of CGFS with a flexible wave foil is established. Based on the fluid-structure coupling analysis method, the three-dimensional flow field of a straight-groove CGFS model is simulated to study the effects of operating and structural parameters on the steady-state characteristics and the effects of gas film thickness, eccentricity, and the number of wave foils on the equivalent stress of the flexible support. Simulation results show that the film stiffness increases significantly when the depth of groove increases. When the gas film thickness increases, the average equivalent stress of the flexible support first decreases and then stabilizes. Furthermore, the number of wave foils affects the average foils thickness. Therefore, when selecting the number of wave foils, the support stiffness and buffer capacity should be considered simultaneously.

scholarly journals Microtubules and microtubule-associated proteins from the nematode Caenorhabditis elegans: periodic cross-links connect microtubules in vitro.

1986 ◽  
Vol 103 (1) ◽  
pp. 23-31 ◽  
Author(s):  
E J Aamodt ◽  
J G Culotti
Keyword(s):  
Caenorhabditis Elegans ◽  
Apparent Molecular Weight ◽  
Cross Link ◽  
Nematode Caenorhabditis Elegans ◽  
Microtubule Associated Proteins ◽  
C Elegans ◽  
Associated Proteins ◽  
Cross Links ◽  
The Cross

The nematode Caenorhabditis elegans should be an excellent model system in which to study the role of microtubules in mitosis, embryogenesis, morphogenesis, and nerve function. It may be studied by the use of biochemical, genetic, molecular biological, and cell biological approaches. We have purified microtubules and microtubule-associated proteins (MAPs) from C. elegans by the use of the anti-tumor drug taxol (Vallee, R. B., 1982, J. Cell Biol., 92:435-44). Approximately 0.2 mg of microtubules and 0.03 mg of MAPs were isolated from each gram of C. elegans. The C. elegans microtubules were smaller in diameter than bovine microtubules assembled in vitro in the same buffer. They contained primarily 9-11 protofilaments, while the bovine microtubules contained 13 protofilaments. The principal MAP had an apparent molecular weight of 32,000 and the minor MAPs were 30,000, 45,000, 47,000, 50,000, 57,000, and 100,000-110,000 mol wt as determined by SDS-gel electrophoresis. The microtubules were observed, by electron microscopy of negatively stained preparations, to be connected by stretches of highly periodic cross-links. The cross-links connected the adjacent protofilaments of aligned microtubules, and occurred at a frequency of one cross-link every 7.7 +/- 0.9 nm, or one cross-link per tubulin dimer along the protofilament. The cross-links were removed when the MAPs were extracted from the microtubules with 0.4 M NaCl. The cross-links then re-formed when the microtubules and the MAPs were recombined in a low salt buffer. These results strongly suggest that the cross-links are composed of MAPs.

scholarly journals Protease-dependent versus -independent cancer cell invasion programs: three-dimensional amoeboid movement revisited

2009 ◽  
Vol 185 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Farideh Sabeh ◽  
Ryoko Shimizu-Hirota ◽  
Stephen J. Weiss
Keyword(s):  
Cancer Cells ◽  
Type I Collagen ◽  
Three Dimensional ◽  
Amoeboid Movement ◽  
Type I ◽  
Collagen Network ◽  
Normal Tissues ◽  
Tissue Invasion ◽  
Absolute Requirement ◽  
Cross Links

Tissue invasion during metastasis requires cancer cells to negotiate a stromal environment dominated by cross-linked networks of type I collagen. Although cancer cells are known to use proteinases to sever collagen networks and thus ease their passage through these barriers, migration across extracellular matrices has also been reported to occur by protease-independent mechanisms, whereby cells squeeze through collagen-lined pores by adopting an ameboid phenotype. We investigate these alternate models of motility here and demonstrate that cancer cells have an absolute requirement for the membrane-anchored metalloproteinase MT1-MMP for invasion, and that protease-independent mechanisms of cell migration are only plausible when the collagen network is devoid of the covalent cross-links that characterize normal tissues.

scholarly journals A Typological Classification for Assessing Farm Sustainability in the Italian Bovine Dairy Sector

2021 ◽  
Vol 13 (13) ◽  
pp. 7097
Author(s):  
Margherita Masi ◽  
Yari Vecchio ◽  
Gregorio Pauselli ◽  
Jorgelina Di Pasquale ◽  
Felice Adinolfi
Keyword(s):  
Structural Characteristics ◽  
Dairy Farms ◽  
Three Dimensions ◽  
Structural Relationships ◽  
Analysis Technique ◽  
The Social ◽  
European Policies ◽  
Farm Sustainability ◽  
Social Environmental ◽  
Cluster Analysis Technique

Italy is among the most important countries in Europe for milk production. The new European policies encourage a transition towards sustainability and are leading European dairy farms to follow new trajectories to increase their economic efficiency, reduce their environmental impact, and ensure social sustainability. Few studies have attempted to classify dairy farms by analyzing the relationships between the structural profiles of farms and the social, environmental, and economic dimensions of sustainability. This work intends to pursue this aim through an exploratory analysis in the Italian production context. The cluster analysis technique made it possible to identify three types of dairy farms, which were characterized on the basis of indicators that represented the three dimensions of sustainability (environmental, social, and economic sustainability) and the emerging structural relationships based on the structural characteristics of the dairy farms. The classification made it possible to describe the state of the art of the Italian dairy sector in terms of sustainability and to understand how different types of farms can respond to the new European trajectories.

Three-Dimensional Localization of DNA Synthesis in Secretory Elements of Adult Female Mouse Submandibular Gland

1990 ◽  
Vol 4 (1) ◽  
pp. 34-44 ◽  
Author(s):  
P.C. Denny ◽  
Y. Chai ◽  
D.K. Klauser ◽  
P.A. Denny
Keyword(s):  
Dna Synthesis ◽  
Submandibular Gland ◽  
Adult Female ◽  
Female Mouse ◽  
Three Dimensional ◽  
Acinar Cells ◽  
Single Pulse ◽  
Duct System ◽  
Duct Cells ◽  
Structural Relationships

A system based in part on three-dimensional structural relationships is described for precisely characterizing the location of cells within secretory complexes of the adult female mouse submandibular gland. The pattern of DNA synthesis during a 90-minute pulse with 3H-thymidine was characterized based upon the above system. Seventy-eight percent of all radiolabeled nuclei were found in the intercalated duct system. One-half of these were in second-order intercalated ducts. DNA synthesis was also observed in acinar cells, granular intercalated duct cells, striated granular duct cells, and granular duct cells. Some secretory complexes contained multiple radiolabeled nuclei, with some of these nuclei in a side-by-side configuration. Approximately one-half of all secretory complexes contained radiolabeled nuclei. A second survey of the frequency of complexes containing radiolabeled nuclei was conducted following four pulses at eight-hour intervals over a 26-hour period. Only about 30% of all complexes contained radiolabeled nuclei. This reduction in the frequency of radiolabeled nuclei when compared with the single pulse suggests the possibility of individual variation. However, a more prolonged period of daily injections for nine days with 3H-thymidine resulted in all but one of the secretory complexes containing radiolabeled nuclei. This latter observation suggests that cell addition in adult submandibular glands is widespread.

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