Complete amino acid sequence of human brain calmodulin

Area of Science:

• Biochemistry
• Molecular Biology
• Neuroscience

Background:

• Calmodulin is a crucial calcium-binding protein involved in numerous cellular processes.
• Understanding calmodulin's structure is essential for deciphering its diverse functions.

Purpose of the Study:

• To determine the complete amino acid sequence of calmodulin isolated from human brain tissue.
• To provide a detailed molecular blueprint for human calmodulin.

Main Methods:

• Peptide generation using enzymatic (trypsin, Staphylococcus aureus V8 protease) and chemical (cyanogen bromide) digestion.
• Peptide purification via reversed-phase high-performance liquid chromatography (RP-HPLC).
• Amino acid sequencing using automated sequenators.

Main Results:

• The complete amino acid sequence of human brain calmodulin was elucidated.
• The protein comprises 148 amino acid residues with a molecular weight of 16,792 Da.
• Identified post-translational modifications include an N-terminal acetyl group and trimethyllysine at position 115.

Conclusions:

• The determined sequence of human brain calmodulin is highly conserved across species, with minor differences in amide group assignments.
• This sequence data serves as a foundational reference for future studies on human calmodulin's structure-function relationships and its role in neurological processes.