Human spleen histone H2B. Isolation and amino acid sequence

Area of Science:

• Molecular Biology
• Evolutionary Biology
• Biochemistry

Background:

• Histones are crucial proteins involved in DNA packaging.
• Understanding histone evolution provides insights into fundamental biological processes.
• Human histone H2B sequence data is essential for comparative evolutionary studies.

Purpose of the Study:

• To determine the amino acid sequence of human histone H2B.
• To compare the human H2B sequence with that of other species, particularly calf thymus.
• To investigate evolutionary conservation of histone H2B.

Main Methods:

• Preparation and separation of whole histone from human spleen.
• Purification of histone H2B using CM-cellulose and Bio-Gel P-60 chromatography.
• Limited chymotryptic digestion, Sephadex G-50 chromatography, and tryptic digestion for peptide analysis.
• Amino acid sequencing of peptides and fragments using column and paper chromatography.

Main Results:

• Human histone H2B was successfully isolated and fragmented.
• Sequence analysis revealed no differences from calf thymus H2B, except for microheterogeneities at residues 39 and 124.
• The highly basic cluster (residues 27-34) was confirmed via staphylococcal protease digestion.

Conclusions:

• The amino acid sequence of human histone H2B is highly conserved, mirroring that of lower mammals.
• This conservation suggests significant evolutionary stability for this essential protein.
• The findings support the role of histone H2B in evolutionary processes.