The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 
 
 

Use of adenosine (5')polyphospho(5')pyridoxals to study the substrate-binding region of glutathione synthetase from Escherichia coli B.

Adenosine(5')polyphospho(5')pyridoxals (APn-PLs, n = 2, 3, 4) were examined for affinity labeling of glutathione synthetase (EC 6.3.2.3) from Escherichia coli B. When the enzyme was incubated with an APn-PL or pyridoxal phosphate in the presence of Mg2+ and then reduced with sodium borohydride, it was most rapidly inactivated by AP4-PL. AP4-PL had a high affinity to the enzyme. The dissociation constant of AP4-PL in the inactivation process was 23 microM. The enzyme was almost completely protected from inactivation by addition of either ATP or gamma-glutamylcysteine. Complete inactivation corresponded to the incorporation of 1 mol of AP4-PL/mol of subunit of the tetrameric enzyme. Proteolytic digestion and sequence analysis of the AP4-PL-labeled enzyme revealed that only Lys-18 was modified. In contrast, the less efficient AP3-PL was found attached to Lys-17, Lys-18, Lys-144, and Lys-148. In the three-dimensional structure of the enzyme, Lys-18 is located close to the putative gamma-glutamylcysteine-binding site, but Lys-17, Lys-144, and Lys-148 are in the mouth of the inner-solvent region, at the bottom of which is the active-site cleft. Furthermore, difference Fourier analysis with the AP4-PL-soaked crystal of the enzyme showed that the adenosine moiety of the bound AP4-PL was in the crevice, which is the ATP-binding site of the enzyme. These results demonstrate the bivalent binding of AP4-PL lying across the gamma-glutamylcysteine- and ATP-binding sites.[1]

References

  1. Use of adenosine (5')polyphospho(5')pyridoxals to study the substrate-binding region of glutathione synthetase from Escherichia coli B. Hibi, T., Kato, H., Nishioka, T., Oda, J., Yamaguchi, H., Katsube, Y., Tanizawa, K., Fukui, T. Biochemistry (1993) [Pubmed]
 
WikiGenes - Universities