Isopenicillin N Synthase – Proposed Mechanism
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HN S H COOH HN AA O O H H Fe 2+ His Asp His H 2 O G ln Fe 2+ His Asp His H 2 O OH 2 + ACV + O 2 HN S H COOH HN AA O O H H Fe 3+ His Asp His H 2 O O O N S H COOH HN AA O O H Fe 2+ His Asp His H 2 O O OH HN S H COOH HN AA O O H Fe 3+ His Asp His H 2 O O OH H N S H COOH HN AA O O H Fe 4+ His Asp His H 2 O O N S COOH HN AA O O H Fe 3+ His Asp His H 2 O OH N S COOH HN AA O O H Fe 2+ His Asp His H 2 O OH -IPN A B C D E F G H -H 2 O -H 2 O Isopenicillin N Synthase – Proposed Mechanism Trapped in year 2 Trapped in year 1 0 0.06 0.1 300 400 500 600 700 Wavelength (nm) A Fe(IV )-Oxo Fe(III)- Superoxo Velocity (mm/s) Spectroscopic Properties of the C-H Cleaving Intermediates
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Isopenicillin N Synthase – Proposed Mechanism. Trapped in year 2. Spectroscopic Properties of the C-H Cleaving Intermediates. Fe(IV)-Oxo. Fe(III)- Superoxo. Velocity (mm/ s ). Trapped in year 1. - PowerPoint PPT Presentation
Transcript of Isopenicillin N Synthase – Proposed Mechanism
HNS
H COOH
HN
AA
O
OH
HFe2+
HisAsp
His
H2O
GlnFe2+
HisAsp
His
H2O
OH2 + ACV + O2HN
S
HCOOH
HN
AAO
OH
HFe3+
HisAsp
His
H2OO O
NS
HCOOH
HN
AAO
OH
Fe2+
HisAsp
His
H2OO OH
HNS
HCOOH
HN
AAO
OH
Fe3+
HisAsp
His
H2OO OH
HNS
HCOOH
HN
AAO
OH
Fe4+
HisAsp
His
H2O O
NS
COOH
HN
AAO
OH
Fe3+
HisAsp
His
H2O OH
NS
COOH
HN
AAO
OH
Fe2+
HisAsp
His
H2OOH
- IPNA B C
D
EFG
H
- H2O
- H2O
Isopenicillin N Synthase – Proposed Mechanism
Trapped in year 2
Trapped in year 1
0
0.06
0.1
300 400 500 600 700
2H-ACV zeroed
2.5ms20ms100ms200ms2s
Wavelength (nm)
Absorbance
Fe(IV)-Oxo
Fe(III)-Superoxo
Velocity (mm/s)
Spectroscopic Properties of the C-H Cleaving Intermediates