scholarly journals Human erythrocyte sorbitol metabolism and the role of sorbitol dehydrogenase

Diabetologia ◽  
1988 ◽  
Vol 31 (10) ◽  
pp. 766-770 ◽  
Author(s):  
Y. Nagasaka ◽  
S. Fujii ◽  
T. Kaneko
Author(s):  
Hideo Hayashi ◽  
Yoshikazu Hirai ◽  
John T. Penniston

Spectrin is a membrane associated protein most of which properties have been tentatively elucidated. A main role of the protein has been assumed to give a supporting structure to inside of the membrane. As reported previously, however, the isolated spectrin molecule underwent self assemble to form such as fibrous, meshwork, dispersed or aggregated arrangements depending upon the buffer suspended and was suggested to play an active role in the membrane conformational changes. In this study, the role of spectrin and actin was examined in terms of the molecular arrangements on the erythrocyte membrane surface with correlation to the functional states of the ghosts.Human erythrocyte ghosts were prepared from either freshly drawn or stocked bank blood by the method of Dodge et al with a slight modification as described before. Anti-spectrin antibody was raised against rabbit by injection of purified spectrin and partially purified.


1990 ◽  
pp. 34-47
Author(s):  
Bertram Lubin ◽  
Frans Kuypers ◽  
Elliott Vichinsky ◽  
Daniel Chiu
Keyword(s):  

1999 ◽  
Vol 19 (4) ◽  
pp. 317-325 ◽  
Author(s):  
Anu Puri ◽  
Peter Hug ◽  
Kristine Jernigan ◽  
Patrick Rose ◽  
Robert Blumenthal

We have recently shown that addition of human erythrocyte glycosphingolipids (GSL) to non-human CD4+ or GSL-depleted human CD4+ cells rendered those cells susceptible to gp120-gp41-mediated cell fusion (Puri et al., BBRC, 1998). One GSL fraction (Fraction 3) isolated from human erythrocyte GSL mixture exhibited the highest recovery of fusion following incorporation into CD4+ non-human and GSL-depleted HeLa-CD4 cells (HeLa-CD4/GSL-). Structural analysis of Fraction 3 showed that this GSL had identical head group as the known GSL, Gal(α1→4)Gal(β1→4)Glc-Ceramide (Gb3) (Puri et al., PNAS, 1998). Here we report that presence of Gb3 in CD4+/CXCR4+ cells but not CD4+/CXCR4- cells allows fusion with HIV-1Lai-envelope glycoprotein expressing cells (TF228). Therefore, Gb3 functions in conjunction with HIV-1 co-receptor, CXCR4 to promote fusion. We propose that Gb3 functions by recruiting CD4 and/or CXCR4 at the fusion site through structurally specific interactions.


1995 ◽  
Vol 269 (5) ◽  
pp. F696-F701
Author(s):  
R. W. Grunewald ◽  
I. I. Weber ◽  
R. K. Kinne

Sorbitol participates in the osmoregulation of several renal cells and has also been found in isolated inner medullary collecting duct (IMCD) cells in primary culture. Therefore, osmotic regulation and distribution of sorbitol and the key enzymes of sorbitol metabolism, aldose reductase and sorbitol dehydrogenase in the renal inner medulla, were investigated in vivo under various osmotic conditions (control, diuresis, antidiuresis). In homogenates of the renal inner medulla of Wistar rats, the sorbitol content correlated with the urine osmolarity [68 +/- 12 mumol/g protein (control), 28 +/- 9 mumol/g (diuresis), 110 +/- 15 mumol/g (antidiuresis)]. Similar results were obtained for the activity of aldose reductase (sorbitol synthesis) [25 +/- 4 U/g (control), 19 +/- 3 U/g (diuresis), and 48 +/- 7 U/g (antidiuresis)]. On the contrary, the activity of sorbitol dehydrogenase (sorbitol degradation) was significantly increased to 1.26 +/- 0.42 U/g under diuretic conditions vs. control (0.84 +/- 0.14 U/g, P < 0.05). These results demonstrate the correlation between the enzymes of sorbitol synthesis and sorbitol degradation in the intact inner medulla and the urine osmolarity in vivo. Whereas the aldose reductase activity was 2.3-fold enriched in IMCD cells, the specific activity of sorbitol dehydrogenase was relatively increased in a preparation of enriched interstitial cells. This distribution was not dependent on the various diuretic conditions. These results indicate that enzymes of synthesis and of degradation of sorbitol are osmotically regulated in vivo. Therefore, the enzymatic activities of sorbitol synthesis appear to be primarily located in epithelial cells, whereas enzymatic activities of sorbitol degradation seem to be localized in interstitial cells of the renal inner medulla.


1993 ◽  
Vol 211 (3) ◽  
pp. 671-681 ◽  
Author(s):  
Philippe GASCARD ◽  
Tadeusz PAWELCZYK ◽  
John M. LOWENSTEIN ◽  
Carl M. COHEN

Author(s):  
CM. Doerschuk ◽  
R.S. Weinstein ◽  
T.L. Steck

A wide variety of perturbations result in aggregation of intramembrane particles (IMP) in human erythrocytes1–3. Experimentally induced aggregation may involve partial removal of the spectrin-actin reticulum from the inner surface of the membrane followed by incubations under conditions which decrease the solubility of spectrin and promote rebinding of spectrin to the cytoplasmic surface2. In this study, we have re-evaluated the role of spectrin in IMP aggregation induced by low pH and by proteolysis1, 3.


1985 ◽  
Vol 101 (4) ◽  
pp. 1379-1385 ◽  
Author(s):  
C L Howe ◽  
L M Sacramone ◽  
M S Mooseker ◽  
J S Morrow

The spectrins isolated from chicken erythrocytes and chicken intestinal brush border, TW260/240, share a common alpha subunit and a tissue-specific beta subunit. The ability of these related proteins to bind human erythrocyte inside out vesicles (IOVs) and human erythrocyte ankyrin in vitro have been quantitatively compared with human erythrocyte spectrin. Chicken erythrocyte spectrin binds human IOVs and human ankyrin with affinities nearly identical to that for human erythrocyte spectrin. TW260/240 does not significantly bind to either IOVs or ankyrin. These results demonstrate a remarkable tissue preservation of ankyrin-binding capacity, even between diverse species, and confirm the role of the avian beta-spectrins in modulating this functionality. Avian brush border spectrin may represent a unique spectrin which serves primarily as a filament cross-linker and which does not interact strongly with membrane-associated proteins.


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