Phsophofructokinase 1 pfk 1 g 142

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: dolase •  Chemical logic: reverse aldol condensaZon; two mechanisms (class I & class II) for stabilizing the enolate intermediate (Schiff base and Zn2+) •  Pathway logic: ring spligng; takes advantage of C2 carbonyl (PGI product, step II) •  Driving force: product removal overcomes unfavorable ΔG´° •  Noteworthy Addi8ons: TIM barrel fold used in apparent convergent evoluZon of class I and class II enzymes V. Triose Phosphate Isomerase (TIM) ΔG´° = 7.5 kJ/mol •  ReacZon proceeds through an enediol intermediate •  Rate is diffusion ­limited (means what?) •  For which the TIM ­barrel fold was named Write a plausible reac1on mechanism V. Triose Phosphate Isomerase (TIM) PDB 2VXN TIM Barrel: 8 ­stranded parallel beta sheet connected by 8 helices Summary TIM •  Chemical logic: stabilizes enediol intermediate •  Pathway logic: coverts 3 ­carbon compounds to the common form used in the next step •  Driving force: highly reversible •  Noteworthy Addi8ons: The original TIM barrel; extremely efficient enzyme Summary: Preparatory Phase (–2 ATP) ΔG´° (kJ/mol)  ­16.7 1.7  ­14.2 23.8 7.5 Why is the overall direction forward?...
View Full Document

Ask a homework question - tutors are online