Ch7-120217 - CHEM 350 Introduction to Biological Chemistry...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: CHEM 350: Introduction to Biological Chemistry Brian Lee, Ph.D. [email protected] Office: Neckers 146G or 324 Phone: 453-7186 Ho urs: 9:30am to 10:30am or by appointment Website: https:/ /online.siu.edu Textbook (required, U.S. edition only) Fundamentals of Biochemistry, 3rd Ed., Voet, Voet & Pratt. Study Guide (recommended) Student Companion to Fundamentals of Biochemistry, 3rd Ed. Help Desk Tuesday 6:30 to 7:30 pm in Neckers 218 Thursday 5:00 to 6:00 pm in Neckers 410 Announcements Undergraduate Research Opportunities Research for credit (such as CHEM 396 or CHEM 496) Student worker ($8.00 per hour) (http://www.siu.edu/~fao/jobs/) Undergraduate Assistantships (http://www.siu.edu/~fao/jobs/) McNair Scholars Program (http://www.siu.edu/~mcnair) REACH Awards Competition (http://www.siu.edu/~reach/) Summer Research Experiences for Undergraduates (REU) Deadline for SIUC REU Program is March 7th For other REU programs, search the National Science Foundation site: http://www.nsf.gov/crssprgm/reu/index.jsp Students must contact the individual sites for information and application materials. NSF does not have application materials and does not select student participants. A contact person and contact information is listed for each site. Assignments Read Chapter 8 Carbohydrates Chapter 8 Problems Student Companion site for Voet, Voet & Pratt http://bcs.wiley.com/he-bcs/Books?action=index&bcsId=4274&itemId=0470129301 Second Midterm Exam, Wednesday February 29th Chapters 6 through 9 All exams are cumulative Help Desk Tuesday 6:30 to 7:30 pm in Neckers 218 Thursday 5:00 to 6:00 pm in Neckers 410 Display of protein antigens - self and non-self: Class I MHC:peptide (surface of all cells) Class II MHC:peptide (surface of immune system cells) Human Class I MHC protein bound to a peptide derived from HIV antigen bound in cleft Antibodies: Immunoglobulin G (IgG) Light chains in purple, Heavy chains in blue and yellow Variable regions in the antigen binding site. Association between antibodies and their antigens involves van der Waals, hydrophobic, hydrogen bonding and ionic non covalent interactions. Note the change in conformation between a and b. The specificity and the strength of the complex is a function of the structural complementarity between the antigen and the antibody. Models of Molecular Recognition: “Lock-and-Key” vs Induced Fit Proposed by Emil Fischer in 1890 Proposed by Daniel Koshland in 1958 Basis of the sequential model for hemoglobin binding to oxygen. Complementarity is pre-existing. Ligand fits into binding with functional groups already arranged for interactions. Both protein and ligand may change conformation to adapt a complementary interaction. Requires protein flexibility and allows for more variation in ligands. An optimal fit for antigen binding can be a combination of “lock and key” and induced fit binding. Antibodies can be designed to catalyze chemical reactions, which implies a change in substrate conformation consistent with induced fit. Agglutination, clumping together of antigens by antibody cross-linking. Serological cross-matching of donor and recipient blood utilizes a test for agglutination prior to transfusion. Agglutination allows macrophages to target multiple pathogenic bacterial cells at once. The Fc regions (not bound to antigen) bind to Fc receptors in macrophages, which engulfs and destroys the virus. Monoclonal Antibodies generate from hybrid mouse cells lymphocytes produce antibody to antigen myeloma cells are immortal cancer cells select hybrid clones by assaying antigen binding affinity Applications: Affinity chromatography, immunoblots and ELISA immunoblots - western blot - PAGE -> nitrocellulose -> antibody ELISA (Enzyme-Linked ImmunoSorbent Assay) ...
View Full Document

Ask a homework question - tutors are online