Amino Acid Sequence of the COOH-terminal Portion of the Arginine-Lysine-rich Histone of Calf Thymus

Abstract 1. Highly purified arginine- and lysine-rich histone was maleylated and then hydrolyzed with trypsin. A large amount of precipitate approximating 35% of the histone appeared during the demaleylation procedure. The precipitate was separated into four fractions on a Sephadex G-50 column and one fraction, tryptic peptide II from the maleylated histone, was found to be the COOH-terminal portion of the histone by analysis of residues released by carboxypeptidases A and B. 2. The sequence of the 48 residues in this fragment determined by sequence analysis and overlapping fragments of tryptic, peptic, and thermolysin digestion products is His-Leu-Gln-Leu-Ala-Ile-Arg-Asn-Asp-Glu-Glu-Leu-Asn-Lys-Leu-Leu-Gly-Lys-Val-Thr-Ile-Ala-Gln-Gly-Gly-Val-Leu-Pro-Asn-Ile-Gln-Ala-Val-Leu-Leu-Pro-Lys-Lys-Thr-Glu-Ser-His-His-Lys-Ala-Lys-Gly-Lys.