2009-10-07_-_Lecture_14

2009-10-07_-_Lecture_14 - Biochemistry 461 FS 2009 Michigan...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Biochemistry 461 FS 2009 Michigan State University The Cytochrome P450 System October 7, 2009 Lecture 14 Cytochrome P450 – General Information • Physiological Role ¾ Ubiquitous enzymes (found in everything from bacteria to humans) ¾ Catalyze a variety of oxidation reactions including hydroxylation of both aliphatic and aromatic compounds, epoxidation reactions, and amine and sulfide oxidations ¾ Catalyze key transformations in biosynthesis and metabolism ± Steroid biosynthesis ± Lipid metabolism ¾ Oxidation of xenobiotics • Localization and nomenclature ¾ Most abundant in liver (approximately 1/3 found in liver) ¾ Also common in adrenal glands, testes, and ovaries ¾ Humans have approximately 60 different types ¾ Nomenclature: family, subfamily, and individual enzyme ± P450 3A4 = family 3, subfamily A, enzyme 4 (by homology) ± P450 3A4 = CYP3A4 C H C OH 2
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
•S t ruc tu re ¾ Heme at the active site ¾ Proximal Cys bound to Fe ± This is where the name P450 is derived ± Pigment whose “reduced + CO” spectrum has a maximum at 450 nm (typically at 420 nm for other heme proteins with His ligation) Cytochrome P450 – General Information 3 σ 2p σ * 2p π 2p π * 2p 3 O 2 2 O 2 1 O 2 2- Bond order bond length (Angstrom) vibrational frequency (cm -1 ) 1.21 1560 Cytochrome P450 – Review of Oxygen σ 2p σ * 2p π 2p π * 2p 3 O 2 •O 2 is in a triplet state. Why does this matter? • What happens when you add electrons to O 2
Background image of page 2
Proposed Mechanism of Cytochrome P450 5 Proposed Mechanism of Cytochrome P450 • How do you cleave the O-O bond to form the reactive intermediate? ¾
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 9

2009-10-07_-_Lecture_14 - Biochemistry 461 FS 2009 Michigan...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online