E-resources
Peer reviewed
-
Kaur, Punit; Kumar, Janesh; Singh, Nagendra; Ethayathulla, Abdul S.; Srivastava, Devendra B.; Sharma, Sujata; Srinivasan, Alagiri; Singh, Tej P.
Acta crystallographica. Section D, Biological crystallography., April 2007, Volume: 63, Issue: 4Journal Article
A 40 kDa glycoprotein (SPG‐40) secreted during involution works as a protective signalling factor through its binding to viable cells. The crystal structure of the native protein has been determined at 2.3 Å resolution. This is the first report on the carbohydrate‐binding properties of SPG‐40; the structure determinations of the complexes of SPG‐40 with four oligosaccharides of different lengths at resolutions ranging from 2.2 to 2.8 Å are described. Carbohydrate‐binding studies with N‐acetylglucosamines (GlcNAcn, n = 3–6) using fluorescence spectroscopy revealed poor binding effects with GlcNAc3 and GlcNAc4, while GlcNAc5 and GlcNAc6 bound to SPG‐40 with considerable strength; the dissociation constants (Kd) were estimated to be 260 ± 3 and 18 ± 4 µM, respectively. SPG‐40 was cocrystallized with GlcNAc3, GlcNAc4, GlcNAc5 and GlcNAc6. The overall structure of native SPG‐40 was essentially similar to that reported previously at low resolution. The structures of its complexes with GlcNAc3, GlcNAc4, GlcNAc5 and GlcNAc6 revealed the positions of these oligosaccharides in the carbohydrate‐binding groove and provided insights into the mechanism of binding of oligosaccharides to SPG‐40, indicating that the preferred subsites in the carbohydrate‐binding groove of SPG‐40 were from −4 to −2. The structure of the protein remained unperturbed upon binding of GlcNAc3 and GlcNAc4, but the structure changed significantly upon binding of GlcNAc5 and GlcNAc6. Significant conformational variations were observed in the sugar‐binding groove: Trp78 partially flipped out of the barrel in GlcNAc5, while in the GlcNAc6 complex a completely flipped‐out Trp78 was observed along with several other conformational changes, including those of Asp186 and Arg242. Such changes upon binding to carbohydrates have not previously been observed in chitin‐hydrolyzing chitinases and reflect less favourable binding of carbohydrates to SPG‐40. As this appears to essentially be a binding protein, this loss of binding affinity might be compensated by other intermolecular interactions such as protein–protein interactions and also by the binding of its own glycan chain.
![loading ... loading ...](themes/default/img/ajax-loading.gif)
Shelf entry
Permalink
- URL:
Impact factor
Access to the JCR database is permitted only to users from Slovenia. Your current IP address is not on the list of IP addresses with access permission, and authentication with the relevant AAI accout is required.
Year | Impact factor | Edition | Category | Classification | ||||
---|---|---|---|---|---|---|---|---|
JCR | SNIP | JCR | SNIP | JCR | SNIP | JCR | SNIP |
Select the library membership card:
If the library membership card is not in the list,
add a new one.
DRS, in which the journal is indexed
Database name | Field | Year |
---|
Links to authors' personal bibliographies | Links to information on researchers in the SICRIS system |
---|
Source: Personal bibliographies
and: SICRIS
The material is available in full text. If you wish to order the material anyway, click the Continue button.