Physical methods for characterization of microbial cell surfaces

1989 ◽  
Vol 45 (11-12) ◽  
pp. 1047-1055 ◽  
Author(s):  
C. Krekeler ◽  
H. Ziehr ◽  
J. Klein
Keyword(s):  
Microbial Cell ◽  
Cell Surfaces ◽  
Physical Methods

scholarly journals Exo-enzymatic addition of diazirine-modified sialic acid to cell surfaces enables photocrosslinking of glycoproteins

2021 ◽  
Author(s):  
Nageswari Yarravarapu ◽  
Rohit Sai Reddy Konada ◽  
Narek Darabedian ◽  
Nichole J. Pedowtiz ◽  
Soumya N. Krishnamurthy ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Cell Surface ◽  
Cell Types ◽  
Cell Surfaces ◽  
Binding Interactions ◽  
Multiple Cell ◽  
Labeling Method ◽  
Cell Surface Glycoconjugates

Glycan binding often mediates extracellular macromolecular recognition events. Accurate characterization of these binding interactions can be difficult because of dissociation and scrambling that occur during purification and analysis steps. Use of photocrosslinking methods has been pursued to covalently capture glycan-dependent interactions in situ however use of metabolic glycan engineering methods to incorporate photocrosslinking sugar analogs is limited to certain cell types. Here we report an exo-enzymatic labeling method to add a diazirine-modified sialic acid (SiaDAz) to cell surface glycoconjugates. The method involves chemoenzymatic synthesis of diazirine-modified CMP-sialic acid (CMP-SiaDAz), followed by sialyltransferase-catalyzed addition of SiaDAz to desialylated cell surfaces. Cell surface SiaDAz-ylation is compatible with multiple cell types and is facilitated by endogenous extracellular sialyltransferase activity present in Daudi B cells. This method for extracellular addition of α2-6-linked SiaDAz enables UV-induced crosslinking of CD22, demonstrating the utility for covalent capture of glycan-mediated binding interactions.

Studies of β-diketone complexes of rhenium. IX. The preparation and characterization of salts of the trans-dihalobis(pentane-2,4-dionato)rhenate(III) anion and an improved preparation of tris(pentane-2,4-dionato)rhenium(III)

1979 ◽  
Vol 57 (10) ◽  
pp. 1252-1256 ◽  
Author(s):  
C. J. L. Lock ◽  
C. N. Murphy ◽  
M. L. Turner
Keyword(s):  
Reducing Agents ◽  
Physical Methods ◽  
Cis And Trans

Salts of the anion Re(C5H7O2)Cl2− have been made by the reduction of both cis- and trans- Re(C5H7O2)Cl2 with a number of different reducing agents. The salts have been examined and characterized by physical methods. An improved preparation for Re(C5H7O2)3 is reported.

Characterization of a 125K glycoprotein associated with bovine epithelial desmosomes

1988 ◽  
Vol 89 (2) ◽  
pp. 207-216
Author(s):  
J.C. Jones
Keyword(s):  
Cell Adhesion Molecule ◽  
Microscopic Analysis ◽  
Epithelial Cell Adhesion Molecule ◽  
Cell Surfaces ◽  
Adhesive Properties ◽  
Western Immunoblotting ◽  
Antibody Preparation ◽  
Cryostat Sections ◽  
Tongue Epithelium

An analysis of the concanavalinA binding polypeptide components of bovine tongue epithelial desmosomes reveals that in addition to the known desmosomal glycoproteins of 100/115K (the ‘desmocollins’), 140K and 160/165K (‘desmoglein 1’) there is an uncharacterized glycoprotein of 125K (K = Mr × 10(−3). This latter polypeptide is immunologically distinct from known desmosomal glycoproteins, as determined by Western immunoblotting, but is recognized by an antibody preparation directed against the epithelial cell adhesion molecule E-cadherin. Moreover, the cadherin antibodies recognize a polypeptide present in bovine muzzle desmosomes that co-migrates with the 125K glycoprotein component of bovine tongue epithelial desmosomes. Upon treatment of bovine tongue desmosomes with a solution containing 9.5 M-urea, the 125K polypeptide becomes enriched in a urea-insoluble, membrane-enriched pelletable desmosomal fraction. Cadherin antibodies and antibodies directed against the 100/115K and 160/165K desmosomal glycoproteins generate similar immunofluorescence staining patterns in cryostat sections of bovine tongue epithelium. However, immunoelectron microscopic analysis of bovine tongue epithelium reveals that cadherin antibodies recognize components located both along the intercellular region of the desmosome and along nondesmosomal cell surfaces whereas antibodies directed against the 100/115K and the 160/165K desmosomal glycoproteins bind specifically to desmosomes. These results suggest that a cadherin-like glycoprotein component may play a role in the adhesive properties of the desmosomes of stratified squamous epithelia.

Physical Methods and Instruments for Characterizing Hailstones

1961 ◽  
Vol 42 (7) ◽  
pp. 452-466 ◽  
Author(s):  
Roland List
Keyword(s):  
Surface Temperature ◽  
Liquid Water ◽  
Physical Characterization ◽  
Aerodynamic Forces ◽  
Thin Sections ◽  
Physical Methods ◽  
Roughness Surface ◽  
Ice Particles ◽  
Free Falling

All methods and instruments currently being used for the physical characterization of hailstones are listed and discussed. Apart from the simpler measurements of diameter, shape, roughness, surface temperature, etc., particular attention is paid to the aerodynamic forces acting on free-falling hailstones and to the way these forces are ascertained. Further paragraphs are devoted to the technique for obtaining thin sections and to their importance in explaining the growth of ice particles. The application of calorimeters and separators in demonstrating the presence of liquid water in the hailstones is also discussed. All these methods can be used for investigating artificially produced ice particles.

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