Biotechnology in Medicine Chapter 12

Learning Outcomes Discuss the scope and role of medical biotechnology in the healthcare industry Explain the function of drugs and discuss how they may be created using combinatorial chemicals Describe the various high-throughput screening processes for potential drug activity Explain the methods for synthesizing peptides and oligonucleotides and discuss the uses of each Detail the multiple uses of antibodies in medical biotechnology and discuss the immune response that results from vaccinations

12.1 Drug Discovery Medical biotechnology includes R&D in the following areas: Causes of diseases and disorders Drugs, pharmaceuticals, and medicines derived from nature or through genetic engineering and/or combinatorial chemistry Disease prevention, vaccines, and gene therapy Diagnostics for medical applications Prosthetics or instruments for replacement or improvement of tissues and organs

Drug Development Sources of Potential Drugs Drugs are chemicals that alter the effects of proteins or other molecules associated with a disease-causing mechanism A drug is usually specific for a particular disease process Sources of Potential Drugs The drug discovery process may involve finding chemical compounds that show activity against one or more molecules associated with a disease. The process is lengthy and often tedious.

Vocabulary Medicine – something that prevents or treats disease or alleviates the symptoms of disease Medical biotechnology – all the areas of research, development, and manufacturing of items that prevent or treat disease or alleviate the symptoms of disease Drug – chemical that alters the effects of proteins or other molecules associated with a disease-causing mechanism Drug discovery – the process of identifying molecules to treat a disease Organic synthesis – the synthesis of drug molecules in a laboratory from simpler, pre-existing molecules Screening – the assessment of hundreds, thousands, or even millions of molecules or samples Pathogenesis – the origin and development of a disease Combinatorial chemistry – the synthesis of larger organic molecules from smaller ones

12.1 Review Questions What kinds of organisms cause diseases? Where are drugs typically discovered? How is aspirin an example of combinatorial chemistry?

Techniques for Creating New Drugs 12.2 Creating Pharmaceuticals through Combinatorial Chemistry Natural compounds must sometimes be modified to be more useful or effective. Techniques for Creating New Drugs Combinatorial chemistry is the process of creating new and varied organic compounds by linking chemical building blocks. Screening Compounds Some drug screening must take place in animal or human cells. Most can be screened on sophisticated instruments.

Vocabulary Parallel synthesis – making large numbers of batches of similar compounds at the same time Library – a collection of compounds, such as DNA molecules, RNA molecules, and proteins Biochip – a special type of microarray that holds thousands of samples on a chip the size of a postage stamp Microarray – a small glass slide or silicon chip with thousands of samples on it that can be used to assess the presence of a DNA sequence related to the expression of certain proteins

12.2 Review Questions What is the value of combinatorial chemistry? How are chemical compound libraries related to high-throughput screening? What is the value of microarray technology?

12.3 Creating Pharmaceuticals through Peptide and DNA Synthesis A peptide can be used in an attempt to identify regulator molecules. A peptide may be used as a vaccine antigen to initiate an antibody response. Peptides are often synthesized for use in the purification of other proteins. Oligonucleotide Synthesis Scientists have learned to make small pieces of DNA, called oligonucleotides.

Vocabulary Peptides – short amino acid chains that are not folded into a functional protein Peptide synthesizer – an instrument that is used to make peptides, up to a maximum of a few dozen amino acids in length Oligonucleotides – segments of nucleic acid that are 50 nucleotides or less in length DNA synthesizer – an instrument that produces short sections of DNA, up to a few hundred base pairs in length

12.3 Review Questions What are three uses of peptides in medicinal biotechnology? How does a peptide synthesizer make peptides? How does a DNA synthesizer make oligonucleotides? Of what value are oligonucleotides?

12.4 Creating Pharmaceuticals by Protein/Antibody Engineering Large proteins can be synthesized through genetic engineering. Antibodies are the most complicated of all proteins. Using Antibodies to Purify Proteins Antibodies are often needed in large quantities.

Using Antibodies to Recognize Molecules Antibodies may be used to recognize molecules in medical research applications. Using Antibodies and Antigens in Vaccines Antibody-antigen reactions are important in disease prevention.

Vocabulary Slow cytometry – a process by which cells are sorted by an instrument, a cytometer, that recognizes fluorescent antibodies attached to surface proteins on certain cells Vaccine – an agent that stimulates the immune system to provide protection against a particular antigen or disease B-cells – specialized cells of the immune system that are used to generate and release antibodies Memory cell – a specialized type of B-cell that remains in the body for long periods of time with the ability to make antibodies to a specific antigen Immunity – protection against any foreign disease-causing agent

12.4 Review Questions How are antibodies used in flow cytometry? How does a vaccine increase the number of antibodies in a person? How does a vaccine provide immunity?

Questions and Comments?