[Distinction between the primary structures of TEM-1 and TEM-2 beta-lactamases]

TEM-1 and TEM-2 beta-lactamases were shown to contain a disulphide bond. When the amino acid compositions of the two proteins were determined, the TEM-2 enzyme exhibited one more lysine residue and one less glutamine (or glutamic acid) residue than the TEM-1 enzyme. This substitution was located at the 14th N-terminal residue, as shown by structural analysis of Staphylococcus aureus protease peptides separated by high performance liquid chromatography. From these results, the Ambler and Scott sequence can be attributed to TEM-2 and the Sutcliffe sequence to TEM-1.