Figure 2
Anomalous density for viscotoxin B2, contoured at 2.8σ. Even though the anomalous signal was too weak for sulfur-SAD phasing, the six disulfide bridges and the S atoms of the sulfate anions are clearly visible in the anomalous density. The density of the sulfate ions is lower because of their higher mobility and because some of them may be partially replaced by phosphate ions. |