FIG. 3.
C4 RP-HPLC separation of fraction H (Fig. 2) following digestion with Lys-C. Eluted peaks (1, 2, and 3) were collected and sequenced. Peak 1 (retention time, 9.45 min) gave a single unequivocal sequence. Peak 2 (retention time, 11.86 min) gave two signals for some cycles of sequence analysis, indicating a mixture of two peptides. However, these two signals were of sufficiently different intensities to allow the two sequences to be assigned (2a and 2b). Peak 3 gave no sequence, suggesting that it contained the undigested N terminally blocked protein. The amino acid sequence (amino acids 31 to 80) of human histone H1d is shown. Amino acid sequences of peptides 1, 2a, and 2b showed 100% homology to histone H1d. In addition, these peptides also showed 100% sequence homology to histones H1b and H1c.