Fractionation and characterization of two morphologically distinct types of cells in Rhizobium japonicum broth culture

1980 ◽  
Vol 26 (2) ◽  
pp. 107-114 ◽  
Author(s):  
S. Shantharam ◽  
J. A. Gow ◽  
A. K. Bal
Keyword(s):  
Star Formation ◽  
Binding Sites ◽  
Broth Culture ◽  
Rhizobium Japonicum ◽  
Nodule Formation ◽  
Bacterial Cells ◽  
Differential Centrifugation ◽  
Capsular Material ◽  
Soybean Lectin

Differential centrifugation of stationary phase broth culture of Rhizobium japonicum yielded two distinct morphological types of bacterial cells, rods, and small coccoid forms with capsulated and non-capsulated cells in each group. The rods usually had polar capsules which resulted in "star" formation. The coccoid bacteria were either free with thick capsular material surrounding the cells or held together in a common capsular sheath forming clusters and chains. 125I soybean lectin bound to the two types of cells. The binding sites were localized in the capsular material as revealed by colloidal gold- and ferritin-labelled lectin. Both fractions were capable of nodule formation in the soybean.

Role of lectins in plant–microorganism interactions. IV. Ultrastructural localization of soybean lectin binding sites on Rhizobium japonicum

1978 ◽  
Vol 24 (7) ◽  
pp. 785-793 ◽  
Author(s):  
H. E. Calvert ◽  
M. Lalonde ◽  
T. V. Bhuvaneswari ◽  
W. D. Bauer
Keyword(s):  
Binding Sites ◽  
Lectin Binding ◽  
Soybean Seed ◽  
Ultrastructural Localization ◽  
Rhizobium Japonicum ◽  
Outer Membranes ◽  
Capsular Material ◽  
Soybean Lectin ◽  
Lectin Binding Sites

The binding of purified, ferritin-labeled soybean seed lectin to the cell surfaces of Rhizobium japonicum 311b 138 has been examined by whole mount, thin section, and freeze-etch electron microscopy. The ferritin-labeled lectin binds in a biochemically specific manner to the capsular material of this bacterium. The lectin does not bind to the outer membranes of the cells or to flagella. Labeled lectin binds to sites throughout the capsular structure, although the density of labeling is somewhat greater on the outer surface of the capsule. Some cells appear to be partially encapsulated. Preservation of the capsular material proved difficult, and methods for retaining most of the capsular material were developed.

scholarly journals Cloning and Characterization of Aedes aegypti Trypsin Modulating Oostatic Factor (TMOF) Gut Receptor

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 934
Author(s):  
Dov Borovsky ◽  
Kato Deckers ◽  
Anne Catherine Vanhove ◽  
Maud Verstraete ◽  
Pierre Rougé ◽  
...  
Keyword(s):  
Binding Sites ◽  
Protein Sequence ◽  
Bacterial Cells ◽  
E Coli ◽  
Trypsin Modulating Oostatic Factor ◽  
High Affinity ◽  
Sds Page ◽  
Atpase Inhibitors ◽  
Kinetics Of

Trypsin Modulating Oostatic Factor (TMOF) receptor was solubilized from the guts of female Ae. Aegypti and cross linked to His6-TMOF and purified by Ni affinity chromatography. SDS PAGE identified two protein bands (45 and 61 kDa). The bands were cut digested and analyzed using MS/MS identifying a protein sequence (1306 amino acids) in the genome of Ae. aegypti. The mRNA of the receptor was extracted, the cDNA sequenced and cloned into pTAC-MAT-2. E. coli SbmA− was transformed with the recombinant plasmid and the receptor was expressed in the inner membrane of the bacterial cell. The binding kinetics of TMOF-FITC was then followed showing that the cloned receptor exhibits high affinity to TMOF (KD = 113.7 ± 18 nM ± SEM and Bmax = 28.7 ± 1.8 pmol ± SEM). Incubation of TMOF-FITC with E. coli cells that express the receptor show that the receptor binds TMOF and imports it into the bacterial cells, indicating that in mosquitoes the receptor imports TMOF into the gut epithelial cells. A 3D modeling of the receptor indicates that the receptor has ATP binding sites and TMOF transport into recombinant E. coli cells is inhibited with ATPase inhibitors Na Arsenate and Na Azide.

Characterization of Thromboxane A2/Prostaglandin H2 Receptors in Porcine Coronary Artery -The Inhibitory Effect of a Novel Dibenzoxepin Derivative, KW-3635

1992 ◽  
Vol 67 (05) ◽  
pp. 582-584 ◽  
Author(s):  
Ichiro Miki ◽  
Akio Ishii
Keyword(s):  
Coronary Artery ◽  
Binding Sites ◽  
Thromboxane A2 ◽  
Inhibitory Effect ◽  
Scatchard Analysis ◽  
Single Class ◽  
Porcine Coronary Artery ◽  
Equilibrium Binding ◽  
H2 Receptors

SummaryWe characterized the thromboxane A2/prostaglandin H2 receptors in porcine coronary artery. The binding of [3H]SQ 29,548, a thromboxane A2 antagonist, to coronary arterial membranes was saturable and displaceable. Scatchard analysis of equilibrium binding showed a single class of high affinity binding sites with a dissociation constant of 18.5 ±1.0 nM and the maximum binding of 80.7 ± 5.2 fmol/mg protein. [3H]SQ 29,548 binding was concentration-dependently inhibited by thromboxane A2 antagonists such as SQ 29,548, BM13505 and BM13177 or the thromboxane A2 agonists such as U46619 and U44069. KW-3635, a novel dibenzoxepin derivative, concentration-dependently inhibited the [3H]SQ 29,548 binding to thromboxane A2/prosta-glandin H2 receptors in coronary artery with an inhibition constant of 6.0 ± 0.69 nM (mean ± S.E.M.).

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