Protein Faltung Flashcards
Was sind 1. 2. 3. 4. Protein Faltungen?
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Proteins are synthesised at ribosomes with a rate of 20 AA / s
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Partial double-bond character of peptide (C-N) bond keeps that in a plane with carbonyl.
Cα-N-bond (Φ) and the Cα-C bond (Ψ)
Anfinsen’s Dogma – folding code
Each protein has only one structure, with the lowest energy, determined by its primary sequence.
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Levinthal’s Paradox –folding speed
Calculation
Faltung
= freie Drehbarkeit der Einfachbindungen der Haupt- und Seitenketten (Rotationsprozess)
Bond strength
NOTES
most common interactions in folded proteins (Hydrophobic interaction, Hydrogen bonds and Electrostatic interaction) are all favoured by the exclusion of water!
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?The Molten Globule State?
Notes?
Compactness promotes native folding
proteins with a ratio of H:P of 1:1 fold rather well
Folding routes as determined by the zipping and assembly method (ZAM). Small pieces that fold fast come together.
Entropy is dominant in larger proteins ➜ release of more free water
Calculation and approximation of an energy surface
The folding process is reflected by a progress variable Q, defined as the fraction of native state contacts that are present at a given state of folding. Q is plotted vs. Energy E and available space P (pressure). (EQP-diagram).
Levinthal-Paradox – Faltungsgeschwindigkeit:
= beschreibt die zunehmende Komplexität der Proteinfaltung zum Erreichen einer bestimmten Proteinstruktur bei zunehmender Kettenlänge
Chaperone
Chaperone sind Proteine, die anderen Proteinen helfen ihre endgültige aktive Konformation zu finden (korrektes Erscheinungsbild), ohne Teil des Endzustandes zu sein (z.B. Hitzeschockproteine; HPS70, HSP90 etc.) = „Faltungshelfer“
What does Levinthal’s paradox say? Is folding in series or in parallel?
VL script 12
