Electrospray deposition as a method to fabricate functionally active protein films.

Electrospray ionization is a routine method in MS analysis of proteins and other biopolymers. Deposition of the electrospray products onto a conductive electrode is suggested here as a means to manufacture functionally active protein films. Recovery of the specific hydrolytic activity of the electrosprayed alkaline phosphatase (AP) was used as a probe for preservation of protein intactness in the electrospray deposition (ESD). It was shown that protein inactivation upon ESD is highly dependent on voltage and current used. Humidity and the presence of protective substances in solution also affect the process. Complete preservation of the enzyme activity was observed when the ESD was performed at low current and humidity in the presence of disaccharides.