Table I

Proteins detected in the histone H2B sample

Deconvolved MH +aMH+calculatedTentative assignmentb
1.13467.513464.5H2B.1 + 14 Dac
2.13480.513478.5H2B.1 + 28 Da
Embedded Image Embedded Image d 13492.5H2B.1 + 42 Da and/or
13496.5H2B.2
4.13511.513510.5H2B.2 + 14 Da and/or
13506.5H2B.1 + 56 Da
5.13525.513524.5H2B.2 + 28 Da and/or
13520.5H2B.1 + 70 Da
Embedded Image Embedded Image 13538.5H2B.2 + 42 Da and/or
13534.5H2B.1 + 84 Da
7.13554.513552.5H2B.2 + 56 Da
8.13568.513566.5H2B.2 + 70 Da
Embedded Image 13581.513580.5H2B.2 + 84 Da
10.13594.513594.5H2B.2 + 98 Da
11.13607.513608.5H2B.2 + 112 Da
12.13621.513622.5H2B.2 + 126 Da
13.13638.513636.5H2B.2 + 140 Da
  • a Automated deconvolution program used—the identification of the monoisotopic peak was problematic due to the overlapping isotope clusters (see Fig. 1).

  • b Assignments are of the major protein species. Other modified species may also be present at lower levels.

  • c Histone H2B has two isoforms (see sequences in Scheme 1).

  • d Starting from here the isotope clusters definitely represent multiple components (see Fig. 2). These may be isobaric, i.e. acetyl vs. Me3 or overlapping clusters of the two isoforms. The major (most abundant) components are underlined.