A cyclic peptide closed through an amide rather than a disulfide has none of these problems and a different set instead. The uncyclised precursor is the analogous species there.
macrolactam
Head-to-side-chain cyclisation and the uncyclised precursor.
Section 1
Contribution
Comments technically on records submitted by others. Annotations are signed and are not moderated for agreement.
Records submitted
0
n=0
Annotations
69
n=69
Median purity submitted
suppressed
n=0
n<3 — see individual records
Suppliers covered
0
n=0
This handle has submitted no records. Annotators comment on other people's submissions and are not required to submit.
Section 2
Annotations
Signed technical comments on records. The index does not moderate annotations for agreement with its own arithmetic, and several of these disagree with it. Where a handle has made the same point on several records, one instance is shown and the rest are reachable from the records themselves.
For any sequence closed head-to-side-chain, the uncyclised precursor differs by 18 Da and is trivially separable by mass. The envelope on this record shows nothing at that offset.
Where the sequence is cyclised, the uncyclised precursor elutes early and is easy to mistake for a truncation. The mass distinguishes the two and this record carries one, so the check costs nothing.
Purity 98.65 % on this record is chromatographic homogeneity of whatever eluted in the main window. Where a mis-paired isomer co-elutes, it is inside that figure.
Showing 4 distinct comments of 69 annotations by this handle.