Term
| Proteins compose ____ of a bio membrane |
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Definition
| - 25-75% upper end for mito mem |
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Term
| A membrane that is ___ prot by mass contains ___ lipid(s) per ___ protein molecule (s) |
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Definition
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Term
| Integral Membrane protein |
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Definition
- tightly associated with lip bilayer
- removal disrupts bilayer
- Transmembrane (cross the mem) versus non trans (just embeded in a leaflet, doesnt cross) |
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Term
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Definition
- Loosely associated, removal doesnt disrupt bilayer
- Change environment to remove pro without effecting bilayer |
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Term
| Lipid Linked Membrane proteins |
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Definition
- Post translational attchment of lipid molecle to soluble proteins
- Can be fatty acylated or Prenylated
- ex; ras due t prenylation and acylation |
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Term
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Definition
- Myristic acid to N-terminus of prot; myristoyl anchor
- Palmitoylatin of internal cys residue; palmitoyl anchor |
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Term
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Definition
| - Cystein residue near c-terminus; ex. farnesyl anchor |
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Term
GPI-linked membrane proteins
- What is it?
- Where does it happen?
- Where on the protein?
- Where is it placed?
- Extra? |
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Definition
| - Attachment of glycosylphosphatidylinositol toprotein - Mod occurs within lumen of ER;C-terminal membrane domain proteolytically removed, ligation of C-terminus of prot to GPI, incorp into lipid raft - Sleeping sickness; variable antigen is GPI linked easily evades immune resp (Tyrpanosome brucei) |
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Term
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Definition
- Tmembrane proteins span the layer 1 time
- 3 distinct domains; E extraceullar non cytosol, TM domain and CT domain
- C terminal faces cytosol is type 1
- N term is cytosolic type 2; cyto-two! |
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Term
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Definition
- AA's tend to have nonpolar side chains, fav interaction with hydrophic core
- Often A-helical; shields polar regions
- Hydrophobicity plot to predict TM regions |
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Term
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Definition
- Span multiple times
- Orientation of TM regions relative to each other is dynamic
- TM can generate cluster to create core sep from hydrophobic lip bilayer; may form a philic pocket/channel in bilayer
ex; CFTR, MDR1, TAP
- Some arrangements of TMD's can be static like B-barrel; each strand penetrates membrane
- Outerface is hydrophobic, inner is phillic |
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Term
| Modifications of Membrane proteins |
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Definition
1) N and O linked glycosilation of extraceullar domains
2) Cystesein residues; extra cel = disulf bond because of oxidizing ennvironment. Intracel = reducing enviro so reduced SH
3) Proteolytic processing of EC domain
4) Phosphorylation of tyrosine, serine or threonine residues of C domain |
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Term
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Definition
- Carb rich coat of the cell
- Made of glycolipids/gprots, and proteoglycans
- Protects the cell
- Allows interactions with environment; ex. selectins bind cell adhesion molecules exp by vasc endothelium |
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Term
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Definition
- Do not flip flop easily
- Rotational and lateral diffusion
- Movement of non-rest proteins suggest olive oil viscosity |
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Term
| Restrict Mobility of proteins |
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Definition
| - large aggregates of memproteins decrease mobility - tethering to intra or extracel elements - Mem protein interacting with proteins in second bilayer - Microdomains like lipid rafts |
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Term
| Asymmetrical Distribution |
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Definition
- Maintained by tight junctions, divides bilayer to domains
- prevent direct movement of proteins and lipids
- Helps polarized cells maintain asym distrib; apical versus baso-lateral |
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Term
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Definition
- Single Bilayer
-Glycophorin (Type 1 single pass TM prot)
- Band 3 (multipass TM, 12 Tm regions)
- Spectrin cytoskeleton |
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Term
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Definition
- Type 1 single pass TMP
- N-linked oligosach in ECD
- Carries antigens
- 1 mill molec/RBC |
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Term
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Definition
- Multi Pass TM protein; 12 TM regions
- Anion transporter
- Aprox 1 mil/RBC
- Interacts with spectrin cytoskeleton |
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Term
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Definition
- Basis of cytoskeleton
- Periph mem protein; attached to glyco and band 3
- Structural integrity of RBC |
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