<italic>In vivo</italic> imaging of penicillin G acylase in mice via a near-infrared fluorescent probe

Abstract

Penicillin G acylase (PGA) is a hydrolytic enzyme, which is also industrially employed in the preparation of semisynthetic penicillin. Abuse of PGA might occur in milk products to decompose the possible excessive antibiotics. Detection of PGA, including in vivo imaging of PGA, is necessary to understand the potential function of this enzyme in living biosystems; however, a near-infrared (NIR) fluorescent probe for PGA is still lacking. On the basis of amino hemicyanine as well as the ability of PGA to hydrolyze phenylacetamide, in this work we have developed a new selective and sensitive NIR fluorescent probe for such a purpose. Combined with in vivo fluorescence imaging system, the probe has been preliminarily used to image the change of the PGA activity in mice. In addition, the NIR feature of our probe makes it of potential use in studying the function of PGA in vivo .