Troubleshooting Nicknames

---

If the command Define Nicknames is dimmed, check for the following:

• A connection point is not present
• More than 2 connection points are defined
• The connection point is not a single bond

In the example below, the functional group was drawn and the entire group selected. Because there is no atom that indicates a connection point, you cannot define a Nickname.

In the example below, the sulfonamide group is attached to an unselected bond, which defines a bond from sulfur as the connection point for the group. This allows you to define a Nickname.

You must leave a bond unselected for each connection point. You cannot define more than two connection points or one attachment point on a single atom in a nickname.

The definition in the figure below was used for the amino acid, Ala. The unselected bond at each end of the structure indicates the connection points-Nitrogen on the left and Carbon on the right.

You can draw a peptide chain by:

• Stringing Nicknames together.

• Stringing Nicknames together in an atom label as long as there is a bond attached.

• Stringing Nicknames together and not including bonds.