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20 Cards in this Set
- Front
- Back
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treatment with papain generates what?
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2 Fab segments; each a Ag binding domain
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what is a Fab segment?
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gen by papain treatment
consists of 1 each: Vh, Vl, Ch1, Cl1 |
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treatment with pepsin generates what?
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1 F(ab)2'; cleaves past disulfide bond that keeps heavy chains together
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what is a F(ab)2' segment?
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gen by pepsin treatment
consists of 2 each: Vh, Vl, Ch1, Cl1 |
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where does C1q (classical complement path) bind?
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Ch2 domain
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how many CDRs are present on 1 Ig?
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6 CDRS: 3 on Vl, 3 on Vh
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what is the significance of beta pleated sheets?
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provide a stable core for variable regions; holds CDRs in position
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what are the approx AA ranges for the 3 CDRs?
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CDR1: 20-30
CDR2: 40-50 CDR3: 90s |
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what are the prominent intermolecular forces b/w Ag and Ig?
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hydrophic
Van der Waals electrostatic H-bonding NO COVALENT BONDS FORMED!!! |
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how do Igs demonstrate flexibility?
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large shift in conformation after Ag binding
EX: BCR when binds Ag, wiggles and sets up lipid rafts-> signal transduction |
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what is the significance of the hinge region?
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allows for flexibility of variable region;
can bind 2 molecules of same Ag (bivalent Ig) |
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what determines the Ig class?
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heavy chain
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what determines that function of the Ig (physiologic and biologic properties)?
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constant regions
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what is the fxn of glycosylation and where does it occur on an Ig?
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fxn: protect fxnal sites (ex: complement binding site Ch2);
protect interchain bonding sites; incr hydrophilicity (solubility); located only in CONSTANT regions |
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what are some features of the IgM hexamer?
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no J chain
not in secretions high levels in some autoimmune diseases |
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what is the bramble receptor?
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receptor that moves Ig across endothelium into extracellular spaces;
receptor for transplacental transfer |
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what is the mxn of the bramble receptor?
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receptors located on endothelium (lumenal side)
2 R bind 1 Ig(G) complex is endocytosed crosses endothelium to enter tissue receptor remains in tact |
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what is the poly-Ig receptor?
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binds polymeric Igs (A,M); req J chain
receptor moves Ig from tissue to lumen (secretions) |
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what is the mxn of the poly-Ig receptor?
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located on lamina propria side of epithelial cell;
1 receptor binds 1 Ig(A) via interaction with J chain; complex endocytosed->lumenal side; IgA dimer rel with secretory component of receptor attached to C-region via disulfide bonds; secretory component protects IgA from proteolysis and stabilizes in lumen |
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what is the Ig superfamily?
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molecules that contain at least 1 Ig domain
involved in cell-cell recog ex: CD3 in TCR, MHC, CAM |
