ABSTRACT
Sulfur-hydrogen compounds include thiols and the thiol acids, RCOSH. Generally, however, in terms of biological interactions it is the thiol group which is the most
significant and so this chapter will deal primarily with thiols. There are a host of protein and nonprotein thiols. These include cysteine, cysteamine, coenzyme A and the tripeptide, glutathione (?-L-glutamyl-L-cysteinylglycine, GSH). In proteins the thiolic functionality carries out a myriad of tasks, from metal binding in the ferridoxins to proteolytic cleavage in the thiol proteases. The thiol group can also be important in hydrogen bond donor/acceptor interactions and has even been discussed as providing an oxidizable switch for protein function.
