scholarly journals Binding of cytochrome b5 to membranes of isolated subcellular organelles from rat liver.

1978 ◽  
Vol 79 (2) ◽  
pp. 291-313 ◽  
Author(s):  
J Remacle

The in vitro incorporation of a well-characterized integral protein cytochrome b5 into membranes of various subcellular organelles was investigated by biochemical and immunochemical methods. Microsomes, peroxisomes, and outer mitochondrial membranes, all containing endogenous cytochrome b5, incorporated large amounts of the hemoprotein in such a way that it was reducible by an inherent NADH cytochrome b5 reductase. Lysosomal membranes did not incorporate cytochrome b5. Inner mitochondrial and Golgi membranes, which do not naturally contain cytochrome b5, bound it in vitro but it was not reduced in the presence of NADH. These results show some discrepancies between the natural localization and the in vitro binding of cytochrome b5. They confirm one aspect of the fluid membrane theory and bring new elements to our understanding of the maintenance of the specific features of the membranes of subcellular organelles with respect to the cell dynamism.

2019 ◽  
Author(s):  
Filip Fratev ◽  
Denisse A. Gutierrez ◽  
Renato J. Aguilera ◽  
suman sirimulla

AKT1 is emerging as a useful target for treating cancer. Herein, we discovered a new set of ligands that inhibit the AKT1, as shown by in vitro binding and cell line studies, using a newly designed virtual screening protocol that combines structure-based pharmacophore and docking screens. Taking together with the biological data, the combination of structure based pharamcophore and docking methods demonstrated reasonable success rate in identifying new inhibitors (60-70%) proving the success of aforementioned approach. A detail analysis of the ligand-protein interactions was performed explaining observed activities.<br>


2004 ◽  
Vol 385 (1) ◽  
pp. 309-317 ◽  
Author(s):  
Zhefeng ZHAO ◽  
Joanna GRUSZCZYNSKA-BIEGALA ◽  
Anna ZOLKIEWSKA

The extracellular domain of integrin α7 is ADP-ribosylated by an arginine-specific ecto-ADP-ribosyltransferase after adding exogenous NAD+ to intact C2C12 skeletal muscle cells. The effect of ADP-ribosylation on the structure or function of integrin α7β1 has not been explored. In the present study, we show that ADP-ribosylation of integrin α7 takes place exclusively in differentiated myotubes and that this post-translational modification modulates the affinity of α7β1 dimer for its ligand, laminin. ADP-ribosylation in the 37-kDa ‘stalk’ region of α7 that takes place at micromolar NAD+ concentrations increases the binding of the α7β1 dimer to laminin. Increased in vitro binding of integrin α7β1 to laminin after ADP-ribosylation of the 37-kDa fragment of α7 requires the presence of Mn2+ and it is not observed in the presence of Mg2+. In contrast, ADP-ribosylation of the 63-kDa N-terminal region comprising the ligand-binding site of α7 that occurs at approx. 100 μM NAD+ inhibits the binding of integrin α7β1 to laminin. Furthermore, incubation of C2C12 myotubes with NAD+ increases the expression of an epitope on integrin β1 subunit recognized by monoclonal antibody 9EG7. We discuss our results based on the current models of integrin activation. We also hypothesize that ADP-ribosylation may represent a mechanism of regulation of integrin α7β1 function in myofibres in vivo when the continuity of the membrane is compromised and NAD+ is available as a substrate for ecto-ADP-ribosylation.


2016 ◽  
Vol 12 ◽  
pp. P144-P144
Author(s):  
Zhizhen Zeng ◽  
Patricia J. Miller ◽  
Brett M. Connolly ◽  
Stacey S. O’Malley ◽  
Idriss Bennacef ◽  
...  

Life Sciences ◽  
1988 ◽  
Vol 42 (21) ◽  
pp. 2097-2104 ◽  
Author(s):  
Thomas Brücke ◽  
Yuan Feen Tsai ◽  
Catherine McLellan ◽  
Weerachai Singhanyom ◽  
Hank F. Kung ◽  
...  

Synapse ◽  
2005 ◽  
Vol 56 (2) ◽  
pp. 100-104 ◽  
Author(s):  
Subroto Ghose ◽  
Masahiro Fujita ◽  
Paul Morrison ◽  
George Uhl ◽  
Dennis L. Murphy ◽  
...  

1984 ◽  
Vol 9 (Supplement 1) ◽  
pp. 98-99 ◽  
Author(s):  
Leslie M. Shaw ◽  
Roy Altman ◽  
Bernard C. Thompson ◽  
Leona Fields

Peptides ◽  
2009 ◽  
Vol 30 (12) ◽  
pp. 2409-2417 ◽  
Author(s):  
Alexandra Evangelou ◽  
Christos Zikos ◽  
Dimitra Benaki ◽  
Maria Pelecanou ◽  
Penelope Bouziotis ◽  
...  

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