Proteins are comprised of chains of amino acids.  The twenty common amino acids found in proteins are encoded by the genetic code.  Protein disulfide bonds are a special type of reversible chemical bond that can form between the sulfur atoms of two nearby cysteine amino acids in response to a chemical reaction known as oxidation.  I and others believe that formation of disulfide bonds in certain key regulatory proteins may play important roles in cellular communication and regulation.  My lab has developed recently a chemical method to trap proteins forming disulfide bonds so that these proteins can be identified and studied further.   We are now applying this method to the capture and identification of proteins from the brain that form disulfide bonds most selectively.