L-Isoleucine → Bacitracin

関与物質

反応手順

Using the same methodology as for Bacitracin A, the location of a modification responsible for the +12 Da difference from Bacitracin A, could be determined. The doubly protonated molecular ion ([M+2H]2+, m/z 718.0) was isolated and fragmented and the resulting product ion (MS/MS) spectrum is shown in FIG. 4B. The spectrum contains a full set of y″ ions with m/z 1349.7/675.82+ (loss of Ile), m/z 1236.7/619.12+ (loss of IleThz), m/z 1123.7 (loss of IleThzLeu), m/z 994.6/498.12+ (loss of IleThzLeuGlu) and m/z 869.6 (loss of IleThzLeuGluMil). These fragment assignments are visualized in FIG. 4A. In addition to the b ions with m/z 566.4 (IleThzLeuGluMil) and m/z 441.3 (IleThzLeuGlu), fragment ions resulting from pairs of bond cleavages can be seen at m/z 227.1 (ThzLeu), m/z 356.1 (ThzLeuGlu) and at m/z 481.2 (ThzLeuGluMil).

情報源と証拠