Hybrid proteins of active-site serine β-lactamase

A recombinant nucleotide sequence which codes upon expression a bifunctional hybrid class A β-lactamase protein, wherein the class A β-lactamase protein bears at least one heterologous sequence in a region located between two neighboring alpha helices of the β-lactamase sequence, wherein the region is selected from the group consisting of:

• a) a region forming a juncture between alpha helix 8 and alpha helix 9 of the TEM-1 β-lactamase;
• and
• b) a region forming a juncture between the alpha helices of said class A β-lactamase, said alpha helices corresponding to the alpha helix 8 and alpha helix 9 of the TEM-1 β-lactamase,
• wherein the hybrid protein has a first function and a second function, wherein the first function is associated with the β-lactamase portion and is selected from the group consisting of:
• c) hydrolyzing β-lactams β-lactamase activity);
• and
• d) binding covalently and in a stable manner to substances selected from the group consisting of β-lactams, derivatives of β-lactams, and inhibitors of β-lactams;
• and wherein the second function is associated with the at least one heterologous sequence having a biological function which is different from the first function.