Bioconjugation

Finally, it should be noted that the term PEGylation is today used very widely and unspecifically. Originally only used for the introduction of PEG chains to proteins and various biobased drugs, now many researchers use the term PEGylation for all kinds of synthetic approaches, which involve the introduction of PEG chains to organic low molar mass or polymeric substances—synthetic or biological—or to material surfaces. In aU these cases, the modification with PEG chains is applied to increase solubility in polar solvents, mainly in water, and to enhance biocompatibility. 

The direct conjugation is a fast and simple approach that is utilized for the formation of bioconjugates often without additional purification. This method can be very efficient in the attachment of low molecular weight molecules to 

---

Bioconjugates Biocontamination Bio-Cor collagen shield Bio-Cox Biocytin Biodegradability... 

Hoen P.A. C., Prince P., Van der Bilt E., Valentijn A. R., Meeuwenoord N.J., Princen H., Bijsterbosch M.K., van der Marel G.A., van Boom J.H., van BerkelT.J.C. Design of a targeted peptide nucleic acid prodrug to inhibit hepatic human microsomal triglyceride transfer protein expression in hepato-cytes. Bioconjug. Chem. 2002 13 295-302. 

Ljungstrom T., Knudsen H., Nielsen P.E. Cellular uptake of adamantyl conjugated peptide nucleic acids. Bioconjug. 

Basu S., Wickstrom E. Synthesis and characterization of a peptide nucleic acid conjugated to a D-peptide analog of insu-lin-like growth factor 1 for increased cellular uptake. Bioconjug. Chem. 1997 8 481-488. 

Gall H, Hoffman TJ, Sieckman GL, Owen NK, Katti KV, Volkert WA (2001) Bioconjugate Chem 12 354... 

Karra SR, Schibli R, Gali H, Katti KV, Hoffman TJ, Higginbotham C, Sieckman GL, Volkert WA (1999) Bioconjugate Chem 10 254... 

Bioconjugates of Compatible Enzymes as Functional Catalysts for Multistep Processes... 

The use of molecular biology methods, described in Section 5.3 seems to be especially worthwhile as it offers novel possibilities of optimization on process adjustment. Directed evolution leads to the formation of new biocatalysts with improved characteristics (selectivity, activity, stability, etc.). Incorporation ofnon-proteinogenic amino acids makes it possible to reach beyond the repertoire of building blocks used by nature. The prospect of bioconjugate preparation offers the possibility to form functional clusters of enzymes and to perform multiple synthetic steps in one pot. 

Tanisaka H, Kizaka-Kondoh S, Makino A, Tanaka S, Hiraoka M, Kimura S (2008) Bioconjug Chem 19 109... 

Brown MD, Schatzlein A, Brownlie A, Jack V, Wang W, Tetley L, Gray AI, Uchegbu IF (2000) Bioconjug Chem 11 880... 

Bull SR, Guler MO, Bras RE et al (2005) Magnetic resonance imaging of self- assembled biomaterial scaffolds. Bioconjug Chem 16 1343-1348... 

---