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Introduction to Studying Proteins. What is going on?. ?. Study Questions. Describe the structure of proteins, including the significance of amino acid R-groups and their impact on the three-dimensional structure of proteins. - PowerPoint PPT Presentation
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Introduction toStudying Proteins
What is going on?
?
Study QuestionsDescribe the structure of proteins, including the significance of amino acid
R-groups and their impact on the three-dimensional structure of proteins.Explain the steps of transcription and translation in protein synthesis.Discuss the role of naturally occurring proteins and recombinant proteins in
biotechnology.Differentiate proteins that function as part of structure, as antibodies, and as
enzymes.Describe the structure of antibodies and explain the relationship between
antibodies and antigens.Discriminate among the classes of enzymes and discuss the effect of
reaction conditions on enzyme activity.Summarize polyacrylamide gel electrophoresis and identify its usefulness for
studying proteins.
5.1 The Structure and Function of Proteins
• Virtually all biotechnology products have something to do with proteins.
• Protein has a three-dimensional structure.
Protein Molecule Structure
• Polymers composed of amino acids• Twenty different kinds of amino acids are found in protein• Most proteins contain tens of hundreds of amino acidsFunction of Structural
ProteinsFor an HIV particle to recognize, attach, and infect a T-helper cell, the gp210 structure must be a precise shape and must exactly match its human cell membrane receptors
Function of Antibody ProteinsRecognize and bind foreign proteins or other molecules (antigens) for removal from the body
Protein Structure and Function Relationship
Secondary Structure
Protein Structure is Complex Primary structure – the order and type of amino acids
found in a polypeptide chain Secondary structure – the structure of a protein (alpha
helix and beta sheets) that results from hydrogen bonding Tertiary structure – the structure of a protein that results
from several interactions, the presence of charged or uncharged “R” groups, and hydrogen bonding
Quaternary structure – the structure of a protein resulting from the association of two or more polypeptide chains
Studying ProteinsWhat and how?
5.2 The Production of Protein
Until recently, proteins could only be made in cells.Now small polypeptide chains can be synthesized in the laboratory.
Overview of Protein Synthesis
Protein synthesis occurs continuously throughout a cell’s lifeEukaryote and prokaryote – protein synthesis is similar
Protein Synthesis in a Eukaryotic Cell. In a eukaryotic cell, DNA is located within chromosomes in the nucleus. The mRNA transcripts carry the DNA code out to the ribosomes, which translate the code into a strand of amino acids.
Genetic code must be rewritten onto a messenger molecule
First Step:
Protein synthesis is a two-step process:
Transcription and Translation
mRNA nucleotide code is rendered into a sequence of amino acids
Second Step:
The Importance of Proteins in Biotech R&DThe ability to synthesize and modify peptides or proteins is crucial to the production of virtually every biotechnology product.
Enzymes: Protein CatalystsEnzymes are proteins that act as catalystsEnzymes are involved in virtually every reaction in a cellMany companies have focused on producing enzymes for saleEnzymes and Their SubstratesThe molecules upon which enzymes act are called substrates
Factors That Affect Enzyme Activity
Applications of Protein Analysis1. Protein profile of cells
and tissues2. A protein’s structure
can help explain its function
3. Chemical processes in cells
4. Evolution and taxonomic relationships
Advanced Protein StudiesA single gene can encode for as many as 50 different protein forms.X-Ray Crystallography
Protein (x-ray) crystallography visualizes the positions of atoms in a molecule based on x-ray wave diffraction, and the constructive and destructive interference that results off the atoms in the sample.
ELISAELISA is one of the most frequently used assays in protein manufacturing.Western BlotsRunning samples on acrylamide gels can provide a great deal of information about the proteins in a sample.
Antibody Proteins
Other Advances and Applications of Biotechnology• Pharmacogenetics• Environmental biotechnology• BiodefensePharmacogenetics – Personalized MedicinesSince every person’s DNA is different, doctors will be able to design and modify drugs to better meet individual needs.
Environmental BiotechThis is a vast field with many applications for monitoring and correcting the health of entire species, populations, communities, and ecosystems.
Biodefense: Protection Against BioterrorismBiodefense is the term for all of the methods used to protect people from exposure to biological agents.