Signals Notebook: Extra bond displayed in peptide backbone when importing HELM strings into ChemDraw JS

Description: When adding a HELM string that defines two connections between a chemical linker and a peptide, the structure may appear to show an additional (third) bond and one of the peptide monomers may also appear to be missing from the displayed backbone.

Cause: This is a visualization issue, the underlying HELM definition is unchanged and the chemical connectivity remains correct. Due to the layout and visualization approach used by ChemDraw/ChemDraw JS to present structures in a compact and readable way, the application may visually compress the peptide backbone, overlap or temporarily hide intermediate monomers, reroute backbone connections.

Solution: Manually adjust the layout by dragging residues or nodes apart, this way you can reveal any overlapping or hidden monomers and set a linear backbone display.