Structural Studies on the Reaction of Isopenicillin N Synthase with a Sterically Demanding Depsipeptide Substrate Analogue

ChemBioChem ◽  
2009 ◽  
Vol 10 (12) ◽  
pp. 2025-2031 ◽  
Author(s):  
Wei Ge ◽  
Ian J. Clifton ◽  
Annaleise R. Howard-Jones ◽  
Jeanette E. Stok ◽  
Robert M. Adlington ◽  
...  
2003 ◽  
Vol 372 (3) ◽  
pp. 687-693 ◽  
Author(s):  
Alexandra J. LONG ◽  
Ian J. CLIFTON ◽  
Peter L. ROACH ◽  
Jack E. BALDWIN ◽  
Christopher J. SCHOFIELD ◽  
...  

Isopenicillin N synthase (IPNS) is a non-haem iron(II) oxidase which catalyses the biosynthesis of isopenicillin N from the tripeptide δ-(l-α-aminoadipoyl)-l-cysteinyl-d-valine (ACV). Herein we report crystallographic studies to investigate the reaction of IPNS with the truncated substrate analogue δ-(l-α-aminoadipoyl)-l-cysteinyl-d-α-aminobutyrate (ACAb). It has been reported previously that this analogue gives rise to three β-lactam products when incubated with IPNS: two methyl penams and a cepham. Crystal structures of the IPNS–Fe(II)–ACAb and IPNS–Fe(II)–ACAb–NO complexes have now been solved and are reported herein. These structures and modelling studies based on them shed light on the diminished product selectivity shown by IPNS in its reaction with ACAb and further rationalize the presence of certain key residues at the IPNS active site.


Biochemistry ◽  
2005 ◽  
Vol 44 (17) ◽  
pp. 6619-6628 ◽  
Author(s):  
Alexandra J. Long ◽  
Ian J. Clifton ◽  
Peter L. Roach ◽  
Jack E. Baldwin ◽  
Peter J. Rutledge ◽  
...  

ChemBioChem ◽  
2006 ◽  
Vol 7 (2) ◽  
pp. 351-358 ◽  
Author(s):  
Adam Daruzzaman ◽  
Ian J. Clifton ◽  
Robert M. Adlington ◽  
Jack E. Baldwin ◽  
Peter J. Rutledge

2004 ◽  
Vol 382 (2) ◽  
pp. 659-666 ◽  
Author(s):  
Annaleise R. GRUMMITT ◽  
Peter J. RUTLEDGE ◽  
Ian J. CLIFTON ◽  
Jack E. BALDWIN

Isopenicillin N synthase (IPNS) is a non-haem iron oxidase that catalyses the formation of bicyclic isopenicillin N from δ-(L-α-aminoadipoyl)-L-cysteinyl-D-valine (ACV). In this study we report a novel activity for the iron of the IPNS active site, which behaves as a Lewis acid to catalyse the elimination of HF from the fluorinated substrate analogue, δ-(L-α-aminoadipoyl)-L-cysteinyl-D-β-fluorovaline (ACβFV). X-Ray crystallographic studies of IPNS crystals grown anaerobically with ACβFV reveal that the valinyl β-fluorine is missing from the active site region, and suggest the presence of the unsaturated tripeptide δ-(L-α-aminoadipoyl)-L-cysteinyl-D-isodehydrovaline in place of substrate ACβFV. 19F NMR studies confirm the release of fluoride from ACβFV in the presence of the active IPNS enzyme. These results suggest a new mode of reactivity for the IPNS iron centre, a mechanism of action that has not previously been reported for any of the iron oxidase enzymes.


2001 ◽  
Vol 79 (5-6) ◽  
pp. 752-759 ◽  
Author(s):  
Anna M Trzeciak ◽  
Hubert Bartosz-Bechowski ◽  
Zbigniew Ciunik ◽  
Katarzyna Niesyty ◽  
Józef J Ziólkowski

PdCl2L2-type complexes with phosphines (L = PPhx(C6F5)3-x (x = 0-3)), phosphites (L = P(OMe)3, P(OPh)3, P(OEt)3), and phosphinites (L = PPh2(OC6F5), PPh2(O-3,5-F2C6H3), PPh2(OEt), PPh2(O-n-Bu), PPh2(O-t-Bu)) were synthesized and characterized by UV-vis and 31P NMR methods. PdCl2L2 complexes with less sterically demanding phosphines (Θ < 140°) exist as cis isomers, which is confirmed by the X-ray structure of cis-PdCl2[PPh2(OEt)]2. These complexes react with CO in the presence of NEt3 forming Pd(CO)xLy (x + y = 4) type carbonyls characterized by IR spectra. All PdCl2L2 complexes studied are active as precursors of benzyl bromide carbonylation catalysts at 40°C and 1 atm CO; however, the activity of the cis isomers is higher than that of the trans isomers. The highest yields of the carbonylation product, phenylacetic acid methyl ester, were obtained using cis-PdCl2[P(OMe)3]2 (92%), cis-PdCl2[P(OPh)3]2 (89%), and cis-PdCl2[PPh2(O-n-Bu)]2 (78%) as catalyst precursors.Key words: palladium complexes, fluorinated phosphines, benzyl bromide carbonylation.


2008 ◽  
Vol 130 (31) ◽  
pp. 10096-10102 ◽  
Author(s):  
Wei Ge ◽  
Ian J. Clifton ◽  
Jeanette E. Stok ◽  
Robert M. Adlington ◽  
Jack E. Baldwin ◽  
...  

FEBS Letters ◽  
2013 ◽  
Vol 587 (16) ◽  
pp. 2705-2709 ◽  
Author(s):  
Ian J. Clifton ◽  
Wei Ge ◽  
Robert M. Adlington ◽  
Jack E. Baldwin ◽  
Peter J. Rutledge

2013 ◽  
Vol 530 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Adam Daruzzaman ◽  
Ian J. Clifton ◽  
Robert M. Adlington ◽  
Jack E. Baldwin ◽  
Peter J. Rutledge

2003 ◽  
Vol 1 (9) ◽  
pp. 1455-1460 ◽  
Author(s):  
Jonathan M. Elkins ◽  
Peter J. Rutledge ◽  
Nicolai I. Burzlaff ◽  
Ian J. Clifton ◽  
Robert M. Adlington ◽  
...  

2010 ◽  
Vol 8 (1) ◽  
pp. 122-127 ◽  
Author(s):  
Wei Ge ◽  
Ian J. Clifton ◽  
Jeanette E. Stok ◽  
Robert M. Adlington ◽  
Jack E. Baldwin ◽  
...  

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