Dielectric spectra broadening as a signature for dipole–matrix interactions. V. Water in protein solutions

2020 ◽  
Vol 153 (4) ◽  
pp. 045102 ◽  
Author(s):  
Larisa Latypova ◽  
Alexander Puzenko ◽  
Evgeniya Levy ◽  
Yuri Feldman
Keyword(s):  
Protein Solutions ◽  
Dielectric Spectra ◽  
Matrix Interactions

Macromolecular crowding and the importance of proper hydration for the structure and dynamics of protein solutions

2018 ◽  
Vol 20 (29) ◽  
pp. 19581-19594 ◽  
Author(s):  
Philipp Honegger ◽  
Michael Schmollngruber ◽  
Othmar Steinhauser
Keyword(s):  
Macromolecular Crowding ◽  
Protein Solutions ◽  
Protein Hydration ◽  
Special Focus ◽  
Computational Studies ◽  
Dielectric Spectra ◽  
Structure And Dynamics

Extensive computational studies of ubiquitin crowding with a special focus on protein hydration directly visible in dielectric spectra.

Characterization of frozen hydrated biological specimens by low-loss EELS

1992 ◽  
Vol 50 (2) ◽  
pp. 1572-1573
Author(s):  
Songquan Sun ◽  
Richard D. Leapman
Keyword(s):  
Water Content ◽  
Direct Method ◽  
Internal Standard ◽  
Dry Weight ◽  
Dark Field ◽  
Protein Solutions ◽  
Subcellular Compartment ◽  
Differential Shrinkage ◽  
Electron Energy Loss

Analyses of ultrathin cryosections are generally performed after freeze-drying because the presence of water renders the specimens highly susceptible to radiation damage. The water content of a subcellular compartment is an important quantity that must be known, for example, to convert the dry weight concentrations of ions to the physiologically more relevant molar concentrations. Water content can be determined indirectly from dark-field mass measurements provided that there is no differential shrinkage between compartments and that there exists a suitable internal standard. The potential advantage of a more direct method for measuring water has led us to explore the use of electron energy loss spectroscopy (EELS) for characterizing biological specimens in their frozen hydrated state.We have obtained preliminary EELS measurements from pure amorphous ice and from cryosectioned frozen protein solutions. The specimens were cryotransfered into a VG-HB501 field-emission STEM equipped with a 666 Gatan parallel-detection spectrometer and analyzed at approximately −160 C.

Use of F9 teratocarcinoma STEM cells to study cell-matrix interactions in the early mouse embryo

1992 ◽  
Vol 50 (1) ◽  
pp. 602-603
Author(s):  
Marc Lenburg ◽  
Rulang Jiang ◽  
Lengya Cheng ◽  
Laura Grabel
Keyword(s):  
Mouse Embryo ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Types ◽  
Embryoid Bodies ◽  
F9 Cells ◽  
Cell Matrix ◽  
Matrix Interactions ◽  
Cell Matrix Interactions ◽  
F9 Teratocarcinoma

We are interested in defining the cell-cell and cell-matrix interactions that help direct the differentiation of extraembryonic endoderm in the peri-implantation mouse embryo. At the blastocyst stage the mouse embryo consists of an outer layer of trophectoderm surrounding the fluid-filled blastocoel cavity and an eccentrically located inner cell mass. On the free surface of the inner cell mass, facing the blastocoel cavity, a layer of primitive endoderm forms. Primitive endoderm then generates two distinct cell types; parietal endoderm (PE) which migrates along the inner surface of the trophectoderm and secretes large amounts of basement membrane components as well as tissue-type plasminogen activator (tPA), and visceral endoderm (VE), a columnar epithelial layer characterized by tight junctions, microvilli, and the synthesis and secretion of α-fetoprotein. As these events occur after implantation, we have turned to the F9 teratocarcinoma system as an in vitro model for examining the differentiation of these cell types. When F9 cells are treated in monolayer with retinoic acid plus cyclic-AMP, they differentiate into PE. In contrast, when F9 cells are treated in suspension with retinoic acid, they form embryoid bodies (EBs) which consist of an outer layer of VE and an inner core of undifferentiated stem cells. In addition, we have established that when VE containing embryoid bodies are plated on a fibronectin coated substrate, PE migrates onto the matrix and this interaction is inhibited by RGDS as well as antibodies directed against the β1 integrin subunit. This transition is accompanied by a significant increase in the level of tPA in the PE cells. Thus, the outgrowth system provides a spatially appropriate model for studying the differentiation and migration of PE from a VE precursor.

Cell matrix interactions in asthma

1997 ◽  
Vol 27 (1) ◽  
pp. 22-27
Author(s):  
K. GOLDRING ◽  
J. A. WARNER
Keyword(s):  
Cell Matrix ◽  
Matrix Interactions ◽  
Cell Matrix Interactions

SHCA PHOSPHOTYROSINE DERIVED SIGNALING IS REQUIRED FOR THE MAINTENANCE OF CARDIAC FUNCTION

2008 ◽  
Vol 31 (4) ◽  
pp. 23
Author(s):  
Rachel Vanderlaan ◽  
Rod Hardy ◽  
Golam Kabir ◽  
Peter Back ◽  
A J Pawson
Keyword(s):  
Extracellular Matrix ◽  
Cardiac Function ◽  
Tyrosine Kinases ◽  
Sh2 Domain ◽  
Scaffolding Protein ◽  
Restricted Domain ◽  
Downstream Signaling ◽  
Matrix Interactions ◽  
Extracellular Matrix Interactions ◽  
Ptb Domain

Background: ShcA, a scaffolding protein, generates signalspecificity by docking to activated tyrosine kinases through distinct phosphotyrosine recognition motifs, while mediating signal complexity through formation of diverse downstream phosphotyrosine complexes. Mammalian ShcA encodes 3 isoforms having a modular architecture of a PTB domain and SH2 domain, separated by a CH1 region containing tyrosine phosphorylation sites important in Ras-MAPK activation. Objective and Methods: ShcA has a necessary role in cardiovascular development^1,2. However, the role of ShcA in the adult myocardium is largely unknown, also unclear, is how ShcA uses its signaling modules to mediate downstream signaling. To this end, cre/loxP technology was employed to generate a conditional ShcA allele series. The myocardial specific ShcA KO (ShcA CKO) and myocardial restricted domain mutant KI mice were generated using cre expressed from the mlc2v locus^3 coupled with the ShcA floxed allele and in combination with the individual ShcA domain mutant KI alleles^2. Results: ShcACKO mice develop a dilated cardiomyopathy phenotype by 3 months of life, typified by depressed cardiac function and enlarged chamber dimensions. Isolated cardiomyocytes from ShcA CKO mice have preserved contractility indicating an uncoupling between global heart function and single myocyte contractile mechanics. Force-length experiments suggest that the loss of shcAmediates the uncoupling through deregulation of extracellular matrix interactions. Subsequent, analysis of the ShcA myocardial restricted domain mutant KImice suggests that ShcA requires PTB domain docking to upstream tyrosine kinases and subsequent phosphorylation of the CH1 tyrosines important for downstream signaling. Conclusion: ShcA is required for proper maintenance of cardiac function, possibly regulation of extracellular matrix interactions. References: 1. Lai KV, Pawson AJ. The ShcA phosphotyrosine docking protein sensitizescardiovascular signaling in the mouse embryo. Genes and Dev 2000;14:1132-45. 2. Hardy WR. et al. Combinatorial ShcA docking interactions supportdiversity in tissue morphogenesis. Science2007;317:251-6. 3.Minamisawa, s. et al. A post-transcriptional compensatory pathway inheterozygous ventricular myosin light chain 2-deficient mice results in lack ofgene dosage effect during normal cardiac growth or hypertrophy. J Biol Chem 1999;274:10066-70.

Moisture-Matrix Interactions in Polymer Based Composite Materials

1995 ◽  
Vol 50 (4) ◽  
pp. 551-571 ◽  
Author(s):  
G. Mensitieri ◽  
M. A. Del Nobile ◽  
A. Apicella ◽  
L. Nicolais
Keyword(s):  
Composite Materials ◽  
Matrix Interactions
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