Affinity chromatography of cysteine-containing histone

Area of Science:

• Biochemistry
• Protein Chemistry
• Chromatography

Background:

• Histones are crucial for DNA packaging.
• Cysteine-containing histone purification presents challenges.
• Affinity chromatography offers specific protein isolation.

Purpose of the Study:

• To develop an efficient affinity chromatography method for purifying cysteine-containing histone.
• To optimize adsorption and elution conditions.
• To validate the purity and identity of the isolated histone.

Main Methods:

• Affinity chromatography utilizing p-mercuribenzoylaminoethyl Sepharose 4B.
• Optimization of buffer conditions (0.1 M citrate, pH 5.5, 5M urea) for adsorption.
• Elution using 0.05 M 2-mercaptoethanol in urea-buffer.
• Further purification via Bio-Gel P-60 chromatography.
• Analysis by polyacrylamide gel electrophoresis and amino acid composition.

Main Results:

• Optimal adsorption achieved in 0.1 M citrate buffer, pH 5.5, with 5M urea.
• Quantitative adsorption and elution demonstrated.
• No adsorption observed with SH-blocked histone or unsubstituted Sepharose.
• Purified histone showed a single band on electrophoresis and correct amino acid composition.

Conclusions:

• Affinity chromatography with mercurial Sepharose is effective for cysteine-containing histone purification.
• The optimized method ensures high purity and recovery.
• This technique provides a reliable means for studying histone structure and function.