Cysteine methyl ester

Methyl cysteinate

Cysteine methyl ester is a chemical compound derived from the amino acid cysteine. It is used in various chemical synthesis and biochemical applications, particularly in the study of protein structure and function. This compound is a methyl ester of cysteine, where the carboxylic acid group (-COOH) of cysteine is converted into a methyl ester (-COOCH3).

Structure and Properties

Cysteine methyl ester has the chemical formula C_4H_9NO_2S. Its structure consists of a cysteine backbone with a methyl group attached to the carboxyl group, making it more hydrophobic than cysteine itself. This modification increases its ability to penetrate cell membranes, making it useful in certain biochemical applications.

Synthesis

Cysteine methyl ester can be synthesized from cysteine through esterification, a common organic reaction where a carboxylic acid reacts with an alcohol, in this case, methanol, in the presence of an acid catalyst. This process converts the carboxyl group of cysteine into a methyl ester group.

Applications

In biochemical research, cysteine methyl ester is used to modify peptides and proteins. It can react with accessible thiol groups in cysteine residues, leading to the formation of disulfide bonds. This property is exploited in the study of protein folding, structure, and stability. Additionally, it is used in the preparation of cysteine-containing peptides and proteins for mass spectrometry analysis, as the esterification can increase the volatility of the compounds.

Safety and Handling

Like many chemical compounds, cysteine methyl ester requires careful handling. It should be stored in a cool, dry place, away from sources of ignition, and handled with appropriate safety equipment, including gloves and eye protection. Safety data sheets (SDS) should be consulted for detailed information on handling and disposal.

See Also

• Amino acid
• Esterification
• Protein structure
• Mass spectrometry