BIO 447 Lecture Notes - Lecture 7: Encephalomyelitis, Growth Factor, Bevacizumab
Document Summary
5 mechanisms generate antibody diversity in na ve b cells: multiple gene segments put together gene segments, p nucleotide addition templated nucleotide addition between joints. Results from asymmetrical cleaving of hairpin structures: exonuclease trimming sometimes occurs at junctions, losing nucleotides, changing reading frames, non-templated n nucleotide addition mediated by tdt activity adding in random nucleotides between joints, somatic hyper-mutation. Combinatorial diversity which heavy chains pair with which light chains. Passive transfer of pooled immunoglobulin from multiple donors to recipient. Contains polyclonal antibodies to infectious organisms, toxins, treating immunodeficiency. Preferred for research/therapeutic purposes because they"re derived from single clone and are specific for a single epitope. Mammalian cells can synthesize nucleotides via 2 pathways: de novo pathway methyl/formyl group is transferred from tetrahydrofolate, salvage pathway converts purines/pyrimidines directly into nucleotides for. Used when de novo pathway is blocked catalyzing enzymes = hgprt, tk.
