Penicillinase, E. clocae

Penicillinase is a specific type of β-lactamase, showing specificity for penicillins, again by hydrolysing the beta-lactam ring. Molecular weights of the various penicillinases tend to cluster near 50kD. Penicillinase was the first β-lactamase to be identified: It was first isolated by Abraham and Chain in 1940 from Gram-negative E. coli even before penicillin entered clinical use,[2] but penicillinase production quickly spread to bacteria that previously did not produce it or produced it only rarely. Penicillinase-resistant beta-lactams such as methicillin were developed, but there is now widespread resistance to even these. Penicillinases are classified as Group 2 along with cephalosporinases, both are inhibited by clavulanic acid, corresponding to the molecular classes A and D reflecting the original TEM and SHV genes. Due to the increasing number of TEM- and SHV-derived β-lactamases, Penicillinases are further divided into the subclass 2a.||Application(s): Suitable for immunoblotting (western or dot blot), ELISA, Conjugation.||Storage and Stability: May be stored at 4°C for short-term only. For long-term storage and to avoid repeated freezing and thawing, aliquot and add glycerol (40-50%). Freeze at -20°C. Aliquots are stable for at least 12 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.