Mammalian Cell Membranes, Volume 1: General Concepts

1976 ◽  
Vol 4 (6) ◽  
pp. 1161-1162
Author(s):  
N. A. GREGSON
Keyword(s):  
Mammalian Cell ◽  
Cell Membranes

scholarly journals Identification of the glucose transporter in mammalian cell membranes with a125I-forskolin photoaffinity label

1988 ◽  
Vol 255 (3) ◽  
pp. 983-990 ◽  
Author(s):  
B E Wadzinski ◽  
M F Shanahan ◽  
R B Clark ◽  
A E Ruoho
Keyword(s):  
Smooth Muscle ◽  
Molecular Mass ◽  
Mammalian Cell ◽  
Cell Membranes ◽  
Plasma Membranes ◽  
Glucose Transporter ◽  
Apparent Molecular Mass ◽  
Synaptic Membranes ◽  
Placental Membranes ◽  
Adipocyte Plasma Membranes

The glucose transporter has been identified in a variety of mammalian cell membranes using a photoactivatable carrier-free radioiodinated derivative of forskolin, 3-[125I]iodo-4-azidophenethylamido-7-O-succinyldeacetylforskoli n ([125I]IAPS-forskolin) at 1-3 nM. The membranes that were photolabelled with [125I]IAPS-forskolin were human placental membranes, rat cortical and cerebellar synaptic membranes, rat cardiac sarcolemmal membranes, rat adipocyte plasma membranes, smooth-muscle membranes, and S49 wild-type (WT) lymphoma-cell membranes. The glucose transporter in plasma membranes prepared from the insulin-responsive rat cardiac sarcolemmal cells, rat adipocytes and smooth-muscle cells were determined to be approx. 45 kDa by SDS/polyacrylamide-gel electrophoresis (PAGE). Photolysis of human placental membranes, rat cortical and cerebellar synaptic membranes, and WT lymphoma membranes with [125I]-IAPS-forskolin, followed by SDS/PAGE, indicated specific derivatization of a broad band (43-55 kDa) in placental membranes and a narrower band (approx. 45 kDa) in synaptic membranes and WT lymphoma membranes. Digestion of the [125I]IAPS-forskolin-labelled placental and WT lymphoma membranes with endo-beta-galactosidase showed a reduction in the apparent molecular mass of the radiolabelled band to approx. 40 kDa. The membranes that were photolabelled with [125I]IAPS-forskolin and trypsin-treated produced a radiolabelled proteolytic fragment with an apparent molecular mass of 18 kDa. [125I]IAPS-forskolin is a highly effective probe for identifying low levels of glucose transporters in mammalian tissues.

Modelling of Fibrillation Induced Selective Cytotoxicity of Phenol Soluble Modulin α3

2019 ◽  
Author(s):  
Mitradip Das ◽  
Sandeep Dash ◽  
B. L. Bhargava
Keyword(s):  
Staphylococcus Aureus ◽  
Mammalian Cell ◽  
Cell Membranes ◽  
Amyloid Fibrils ◽  
Hydrophobic Interactions ◽  
Stabilization Energy ◽  
Selective Toxicity ◽  
Selective Cytotoxicity ◽  
Future Drug ◽  
Α Helix

Phenol soluble modulin (PSM) α3, the most toxic member of α-toxin in <i>Staphylococcus aureus</i> bacteria, has been recently found to form cross-α amyloid fibrils and is selectively toxic to the mammalian cell membranes. In this work, it has been discovered that hydrophobic interactions play a major role in fibril formation of PSM-α3 strands, with<br>stabilization energy of 28.7 kCal/mol. We considered two model bilayers mimicking mammalian and bacterial cell membranes, and found that single α-helix strand penetration is energetically unfavourable in both of them. Hence, we propose a simple model using energetics to understand the reason for selective toxicity of the peptide to the mammalian cell membrane. This study, besides enhancing the understanding of PSM-α3, can also act as a stepping stone in future drug development against <i>​S. aureus.</i> ​<br><br>

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