Mannan-penicillin G acylase neoglycoproteins were prepared by the conjugation of Saccharomyces cerevisiae mannan with enzyme penicillin G acylase using the reductive amination method. Eight neoglycoproteins preparations were obtained after gel chromatography. The preparations contained from 42 to 67% (w/w) saccharides and their molar masses varied from 283 to over 1000 kDa. Significant biospecific interaction of separated fractions with the lectin concanavalin A was evaluated by the precipitation and sorption method (equilibrium constants) and further characterized using surface plasmon resonance to determine kinetic association and dissociation constants. K (D) was determined over the range 10(-7) M. High-molar-mass preparations appeared to be more suitable for preparation of stable and active complexes with concanavalin A for prospective use as a penicillin G acylase biocatalyst in enzyme reactors. The enzyme stability of such complexes was significantly increased compared with the original neoglycoprotein. Lower-molar-mass preparations were more suitable for applications such as biocatalysts in bioanalytical devices.