Review Biotechnology and genetic engineering in the new drug development. Part I. DNA technology and recombinant proteins Agnieszka Stryjewska 1 , Katarzyna Kiepura 1 , Tadeusz Librowski 2 , Stanis³aw Lochyñski 3 Department of Bioorganic Chemistry, Faculty of Chemistry, Wroc³aw University of Technology, Wyb. Wyspiañskiego 27, PL 50-370 Wroc³aw, Poland Department of Radioligands, Medical College, Faculty of Pharmacy, Jagiellonian University, Medyczna 9, PL 30-688 Kraków, Poland Institute of Cosmetology, Wroc³aw College of Physiotherapy, Koœciuszki 4, PL 50-038 Wroc³aw, Poland Correspondence: Stanis³aw Lochyñski, e-mail: s.lochynski@wsf.wroc.pl; Tadeusz Librowski, e-mail: mflibrow@cyf-kr.edu.pl Abstract: Pharmaceutical biotechnology has a long tradition and is rooted in the last century, first exemplified by penicillin and streptomycin as low molecular weight biosynthetic compounds. Today, pharmaceutical biotechnology still has its fundamentals in fermentation and bioprocessing, but the paradigmatic change affected by biotechnology and pharmaceutical sciences has led to an updated defini- tion. The biotechnology revolution redrew the research, development, production and even marketing processes of drugs. Powerful new instruments and biotechnology related scientific disciplines (genomics, proteomics) make it possible to examine and exploit the behavior of proteins and molecules. Recombinant DNA (rDNA) technologies (genetic, protein, and metabolic engineering) allow the production of a wide range of pep- tides, proteins, and biochemicals from naturally nonproducing cells. This technology, now approximately 25 years old, is becoming one of the most important technologies developed in the 20 century. Pharmaceutical products and industrial enzymes were the first biotech products on the world market made by means of rDNA. De- spite important advances regarding rDNA applications in mammalian cells, yeasts still represent attractive hosts for the production of heterologous proteins. In this review we describe these processes. Key words: biotechnology, recombinant DNA technology, directed mutagenesis, aranesp, activase Introduction Biotechnology is being defined as organisms or bio- logical molecules, which are used in the industrial production. This term includes processes used for centuries, such as the production of alcohol, as well as the discovery in more recent years of genetic engi- neering [30, 40, 46]. Biotechnology in the pharmacol- ogy is being called biotechnology pharmaceutical, which is producing biopharmaceuticals. These are proteins with therapeutic meaning and recently nu- 1075