membrane structure lecture 4 chapter 10. lipid classification phosphoglycerides sphingolipids...

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MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10

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Page 1: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

MEMBRANE STRUCTURE

LECTURE 4CHAPTER 10

Page 2: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

LIPID CLASSIFICATION

• PHOSPHOGLYCERIDES• SPHINGOLIPIDS• STEROIDS

Page 3: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

PHOSPHOGLYCERIDES

Page 4: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

SPHINGOLIPIDS

Page 5: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

STEROIDS

Page 6: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

MEMBRANE BILAYER

Page 7: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

BILAYER STRUCTURE OF BIOMEMBRANRANES

Page 8: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

FORMATION OF PURE PHOSPHOLIPID BILAYERS

Page 9: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

PROPERTIES OF MEMBRANES

• HYDROPHOBIC CORE IS AN IMPERMEABLE BARRIER

• STABILITY – Van der Waals interaction, and hydrophobic interaction stabilize the fatty acyl groups whereas ionic and hydrogen bonds stabilize the polar head groups

• PHOSPHOLIPID BILAYERS SPONTANEOUSLY FORM CLOSED SEALED COMPARTMENTS

Page 10: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

MEMBRANE BUDDING AND FUSION

Page 11: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

CYTOSOLIC AND EXOPLASMIC FACES ARE CONSERVED

Page 12: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

LIPID COMPOSITION IN THE EXOPLASMIC AND CYTOSOLIC FACES

OF THE MEMBRANES

Page 13: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

HOW LIPIDS AFFECT CURVATURE AND THICKNESS OF MEMBRANES

Page 14: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS
Page 15: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

PHOSPHOLIPID BILAYER- lateral and rotational movement

Page 16: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

FRAP EXPERIMENTS

Page 17: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

FRAP EXPERIMENT (cont’d)

Page 18: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

MEMBRANE PROTEINS

• INTEGRAL or TRANS – MEMBRANE PROTEINS• LIPID-ANCHORED MEMBRANE PROTEINS• PERIPHERAL MEMBRANE PROTEINS

Page 19: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

Integral membrane proteins

• Contain membrane spanning α- helices• 20-25 hydrophobic uncharged amino acids

(3.75 nm)• Segment is perpendicular to the membrane or

is at an oblique angle• Amino peptide bonds in the interior of the α-

helix• Hydrophobic side chains interact with fatty

acyl groups

Page 20: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

GLYCOPHORIN A – single pass integral membrane protein

Page 21: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

Multipass Transmembrane Protein

Page 22: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

Multiple membrane spanning β strands

• Porins• Gram-negative bacteris, outer membrane of

mitochondria and chloroplasts• Trimers of identical subunits• Each subunit – 16 beta strands that twist to

form a barrel-shaped structure• Barrel - Hydrophilic interior and hydrophobic

exterior

Page 23: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

Single subunit of outer membrane Porin from E.coli

Page 24: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

PERIPHERAL MEMBRANE PROTEINS

Page 25: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

HOW IS BLOOD GROUP DETERMINED?

Page 26: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS
Page 27: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

Mechanism of action of Phospholipase A

Page 28: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

SOLUBILIZATION OF MEMBRANES

Page 29: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

BINDING OF FATTY ACID TO THE FATTY –ACID-BINDING PROTEIN

Page 30: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

PHOSPHOLIPID BIOSYNTHESIS

Page 31: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

CHOLESTEROL BIOSYNTHESIS

Page 32: MEMBRANE STRUCTURE LECTURE 4 CHAPTER 10. LIPID CLASSIFICATION PHOSPHOGLYCERIDES SPHINGOLIPIDS STEROIDS

MECHANISM OF CHOLESTEROL AND PHOSPHOLIPID TRANSPORT