Login

Join for Free!
119314 members
table of contents table of contents

A report on the crystal structure of a lectin isolated from Canavalia …


Biology Articles » Mycology » Structure of a lectin from Canavalia gladiata seeds: new structural insights for old molecules » Figures

Figures
- Structure of a lectin from Canavalia gladiata seeds: new structural insights for old molecules

..................................................

Figure 1 Crystal structure of CGL-αMM. The vision of the Abu position can be seen in the canonical dimmer between the monomers at hydrophobic cavity. Abu is displayed in yellow and α-methyl-mannoside is in blue.

..................................................

Figure 2 CGL hydrophobic pocket. Abu electron density (2Fo-Fc) map countered at 1 σ.

..................................................

Figure 3 Abu electron density in hydrophobic pocket. (A) Fo-Fc omit map of Abu in CGL structure. (B) Fo-Fc electron density map of CGL structure solved at room temperature (without glycerol as cryoprotectant) at 3.0 Å

..................................................

Figure 4 Stereo view of Abu ligand site. H-bonds stabilize the Abu (magenta) in the pocket after the anchoring by hydrophobic interactions. The pocket is formed in the monomers interface, which build the canonical dimers of CGL, inside the hydrophobic cavity. Asp 139 from one chain and Ala 125 from the other monomer chain interacts with abu by H-bonds. Two interstitial water molecules (red balls) perform H-bonds with the amino and carboxyl groups of abu. The hydrophobic contacts are established by abu and Leu 126 and Val 179 from the same chain.

..................................................

Figure 5 CGL mass spectrometry analysis. (A) Mass spectrometry analysis of CGL reveals peaks of ions with charge from +18 (m/z = 1419.8669) to + 28 (m/z = 913.1152). (B) Deconvolution of CGL spectrum, showing the double-charged ion (m/z = 12770.0010) and the mono-charged ion (m/z = 25541.0020) which represents the exact mass of the protein. (C) The Abu signature is represented by the peak with m/z (+H) = 104.1131 ± 0.1 M. The presence of Abu in the CGL structure was confirmed by MS/MS analysis. The spectrum reveals an Abu fragmentation ion displaying m/z = 86.05 ± 0.1, this mass referred to Abu molecular mass with a common loss of a water group (~18 Da).

..................................................

Figure 6 Schematic graph of the interaction mechanism between the lectin and Abu shows the relation of these molecules and the ISR in leguminous. The figures inside the frames represent the molecule forms that occur in high concentration during the plant ontogeny. (●) represents the Abu concentration during the seeding as reported by Rozan et al.[12]; (■) refers to the lectin concentration determined by Da Silva et al.[22]; and (▲) gives the concentration of compounds related to pathogens response and stress events in accord to Boege K & Marquis R J[11].

..................................................


rating: 4.43 from 21 votes | updated on: 3 Sep 2007 | views: 10766 |

Rate article:







excellent!bad…