scholarly journals Unique Molecular Architecture of Silk Fibroin in the Waxmoth,Galleria mellonella

2002 ◽  
Vol 277 (25) ◽  
pp. 22639-22647 ◽  
Author(s):  
Michal Z̆urovec ◽  
František Sehnal
Keyword(s):  
Silk Fibroin ◽  
Galleria Mellonella ◽  
Molecular Architecture

scholarly journals Molecular architecture of silk fibroin of Indian golden silkmoth, Antheraea assama

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Adarsh Gupta K ◽  
Kazuei Mita ◽  
Kallare P. Arunkumar ◽  
Javaregowda Nagaraju
Keyword(s):  
Silk Fibroin ◽  
Molecular Architecture ◽  
Antheraea Assama

Formation of Silk Monolayers

1992 ◽  
Vol 292 ◽  
Author(s):  
Wayne S. Muller ◽  
Lynne A. Samuelson ◽  
Stephen A. Fossey ◽  
David L. Kaplan
Keyword(s):  
Silk Fibroin ◽  
Membrane Properties ◽  
Electron Diffraction Data ◽  
Attenuated Total Reflectance ◽  
Spectrometric Analysis ◽  
Molecular Architecture ◽  
Langmuir Blodgett ◽  
Transmission Electron ◽  
Pressure Area ◽  
Ellipsometry Data

AbstractCast silk membranes exhibit useful properties. However, there is limited control over the molecular architecture in these structures. The Langmuir-Blodgett technique can enhance the control of the membrane structure and allow improved control over membrane properties. We have formed natural silk monolayers using the Langmuir technique. Silk fibroin, regenerated from Bombvx mori cocoons, formed stable monolayers evident from pressure/area isotherms. Multilayers of the silk fibroin monolayers were deposited on a number of substrates and characterized. Transmission Electron Microscopy (TEM) and ellipsometry data provide basic information about the physical characteristics of the monolayer. Preliminary analysis of electron diffraction data of the monolayer indicate polycrystalline structure, consistent with the known structure of silk. Infrared spectrometric analysis of the monolayer using Attenuated Total Reflectance (ATR) gave wavenumbers for Amide I, II, III and V bands which compare with the silk II conformation reported for cast silk membranes.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

Exploration of cell wall architecture with the rapid-freeze deep-etch technique

1993 ◽  
Vol 51 ◽  
pp. 128-129
Author(s):  
Béatrice Satiat-Jeunemaitre ◽  
Chris Hawes
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Cell Biology ◽  
Molecular Model ◽  
Three Dimensional ◽  
Secretory Activity ◽  
Wall Structure ◽  
Specimen Preparation ◽  
Molecular Architecture ◽  
Plant Cell Walls

The comprehension of the molecular architecture of plant cell walls is one of the best examples in cell biology which illustrates how developments in microscopy have extended the frontiers of a topic. Indeed from the first electron microscope observation of cell walls it has become apparent that our understanding of wall structure has advanced hand in hand with improvements in the technology of specimen preparation for electron microscopy. Cell walls are sub-cellular compartments outside the peripheral plasma membrane, the construction of which depends on a complex cellular biosynthetic and secretory activity (1). They are composed of interwoven polymers, synthesised independently, which together perform a number of varied functions. Biochemical studies have provided us with much data on the varied molecular composition of plant cell walls. However, the detailed intermolecular relationships and the three dimensional arrangement of the polymers in situ remains a mystery. The difficulty in establishing a general molecular model for plant cell walls is also complicated by the vast diversity in wall composition among plant species.

Molecular architecture and functions of the neuronal cytoskeleton

1990 ◽  
Vol 48 (3) ◽  
pp. 2-3
Author(s):  
Nobutaka Hirokawa
Keyword(s):  
Major Elements ◽  
Molecular Structures ◽  
Organelle Transport ◽  
Molecular Architecture ◽  
Neuronal Morphogenesis ◽  
Microtubule Associated Proteins ◽  
Associated Proteins ◽  
And Function ◽  
Small Clusters

In this symposium I will present our studies about the molecular architecture and function of the cytomatrix of the nerve cells. The nerve cell is a highly polarized cell composed of highly branched dendrites, cell body, and a single long axon along the direction of the impulse propagation. Each part of the neuron takes characteristic shapes for which the cytoskeleton provides the framework. The neuronal cytoskeletons play important roles on neuronal morphogenesis, organelle transport and the synaptic transmission. In the axon neurofilaments (NF) form dense arrays, while microtubules (MT) are arranged as small clusters among the NFs. On the other hand, MTs are distributed uniformly, whereas NFs tend to run solitarily or form small fascicles in the dendrites Quick freeze deep etch electron microscopy revealed various kinds of strands among MTs, NFs and membranous organelles (MO). These structures form major elements of the cytomatrix in the neuron. To investigate molecular nature and function of these filaments first we studied molecular structures of microtubule associated proteins (MAP1A, MAP1B, MAP2, MAP2C and tau), and microtubules reconstituted from MAPs and tubulin in vitro. These MAPs were all fibrous molecules with different length and formed arm like projections from the microtubule surface.

Projected Structure of the Surface Protein of Sulfolobus Spec. B12 Determined to a Resolution of 1.0 NM by Cryo-Electronmicroscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 102-103
Author(s):  
G. Lembcke ◽  
F. Zemlin
Keyword(s):  
Low Dose ◽  
Maximum Dose ◽  
Three Dimensional ◽  
Surface Protein ◽  
Protein S ◽  
Radiation Sensitivity ◽  
Specimen Preparation ◽  
Molecular Architecture ◽  
High Radiation ◽  
Fritz Haber

The thermoacidophilic archaebacterium Sulfolobus spec. B12 , which is closely related to Sulfolobus solfataricus , possesses a regularly arrayed surface protein (S-layer), which is linked to the plasma membrane via spacer elements spanning a distinct interspace of approximately 18 nm. The S-layer has p3-Symmetry and a lattice constant of 21 nm; three-dimensional reconstructions of negatively stained fragments yield a layer thickness of approximately 6-7 nm.For analysing the molecular architecture of Sulfolobus surface protein in greater detail we use aurothioglucose(ATG)-embedding for specimen preparation. Like glucose, ATG, is supposed to mimic the effect of water, but has the advantage of being less volatile. ATG has advantages over glucose when working with specimens composed exclusively of protein because of its higher density of 2.92 g cm-3. Because of its high radiation sensitivity electromicrographs has to be recorded under strict low-dose conditions. We have recorded electromicrographs with a liquid helium-cooled superconducting electron microscope (the socalled SULEIKA at the Fritz-Haber-lnstitut) with a specimen temperature of 4.5 K and with a maximum dose of 2000 e nm-2 avoiding any pre-irradiation of the specimen.

Die Raupe Galleria mellonella als Infektionsmodell

2017 ◽  
Author(s):  
M Olsowski ◽  
J Steinmann ◽  
D Theegarten
Keyword(s):  
Galleria Mellonella

Multi-Stimuli-Responsive Mesoporous Membranes and Effect of Molecular Architecture on Thermo- and pH-Responsive Behavior of the grafted Block Copolymer brushes

2019 ◽  
Author(s):  
Yanchun Tang ◽  
Kohzo Ito ◽  
Hideaki Yokoyama
Keyword(s):  
Polymer Brushes ◽  
Diblock Copolymers ◽  
Neutron Reflectivity ◽  
Molecular Architecture ◽  
Stimuli Responsive ◽  
Responsive Polymer ◽  
The Matrix ◽  
Stable Part ◽  
Copolymer Brushes ◽  
Mesoporous Membranes

In this study, we prepared ultrafiltration membranes with a decoupled responses of filtration property to temperature and pH. The membrane preparation method was developed based on our previous work. We utilized methanol-supercritical carbon dioxide (methanol-scCO<sub>2</sub>) selective swelling method to introduce nanopores to block copolymers containing poly(diethylene glycol) methyl ether methacrylate (PMEO<sub>2</sub>MA), poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) and polystyrene (PS) blocks. Formation of the mesoporous barrier layer with PS being the mechanically stable part of the matrix was driven by selective swelling of the PMEO<sub>2</sub>MA-b-PDMAEMA domains. Due to the selective swelling of PMEO<sub>2</sub>MA or PDMAEMA domains to introduce pores, the interior of the pores are covered with PMEO<sub>2</sub>MA or PDMAEMA blocks after pore formation. The PMEO<sub>2</sub>MA-b-PDMAEMA polymer brushes are naturally attached on the pore walls and worked as functional gates. PMEO<sub>2</sub>MA is a non-toxic, neutral thermo-responsive polymer with LCST at 26 ᴼC. PDMAEMA is a typical weak polyelectrolyte with pK<sub>a</sub> value at 7.0-7.5 and also a thermo-responsive polymer revealed a LCST of 20-80 °C in aqueous solution. Therefore, these membranes were expected to have multi dimensions as function of the combination of temperature and pH. Moreover, to understand the detail of the temperature and pH depended conformation transitions of PMEO<sub>2</sub>MA-b-PDMAEMA brushes, those diblock copolymers were end-tethered on flat substrates and analyzed via neutron reflectivity (NR).

INFLUÊNCIA DO SUBSTRATO E DA LUMINOSIDADE NA INFECÇÃO DE NEMATOIDES ENTOMOPATOGÊNICOS EM Galleria mellonella (LEPIDOPTERA: PYRALIDAE)

2018 ◽  
Vol 20 (2) ◽  
pp. 91-101
Author(s):  
Andressa Lima de Brida ◽  
Silvia Renata Siciliano Wilcken ◽  
Luis Garrigós Leite
Keyword(s):  
Galleria Mellonella ◽  
Steinernema Carpocapsae ◽  
Steinernema Feltiae ◽  
Lepidoptera Pyralidae

Nematoides entomopatogênicos (NEPs) são alternativas eficientes para o controle de pragas. O emprego de novas técnicas da produção in vivo, permite o progresso da tecnologia de formulação de bioinseticidas. O objetivo do trabalho, foi avaliar a influência da luminosidade e do substrato na capacidade de infecção de juvenis infectantes (JIs) de Steinernema brazilense IBCBn 06, Steinernema carpocapsae IBCBn 02, Steinernema feltiae IBCBn 47 e Heterorhabditis amazonensis IBCBn 24 em lagartas de Galleria mellonella (Lepidoptera: Pyralidae). O delineamento experimental foi inteiramente casualizado com quatro tratamentos e oito repetições. As parcelas, constituídas por placa de Petri com, substrato-areia e substrato-papel filtro, com e sem luminosidade, inoculados com suspensão de 1,5 mL contendo 400JIs e quatro lagartas de G. mellonella. O número de JIs foi quantificado após a mortalidade das lagartas. A taxa de infecção de JIs de S. carpocapsae IBCBn 02 e S. feltiae IBCBn 47 variaram de 2,14 a 3,28 e de 11,04 a 13,09 JIs/lagarta. O substrato-areia com e sem luminosidade permitiu a maior taxa de infeção dos JIs de S. brazilense IBCBn 06 de 7,86 e 9,44 JIs/lagarta, e 13,49 JIs/lagarta com luminosidade para H. amazonensis IBCBn 24. O substrato-areia, permite a maior taxa de infecção por JIs de NEPs.

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