70
T. Yumura et al.
Despite increasing our understanding on the methane hydroxylation on MMO,
there still remains issues. Reliability of the computational models relies on the molecular structures developed by spectroscopic and X-ray crystallographic analyses.
Recent revisiting studies of the intermediate Q by X-ray absorption spectroscopy
(XAS) [135, 136] indicated that the previously proposed structure may be incorrect
and revised models have been proposed. However, again the new proposal by XAS
is incompatible with the resonance Raman study on the catalytic cycle of sMMO
[137]. The structure of the copper active site of pMMO is under debate as well.
While the initial X-ray crystal structure showed a dinuclear copper center, recent
analyses indicated that a mononuclear copper is involved in the active site [138].
Thus, it remains challenges for computational chemists to perform further analyses
on the follow up information.
Spectroscopic and X-ray crystallographic investigations of MMO have provided
us valuable information for theoretical studies of ours and others. However still, a
question arises as to if a major species that is visible by spectroscopy and X-ray
crystallography is really a functional species or not. We cannot eliminate a possibility that a minor speices that escapes from experimental characterizations is a
critical component for function of the enzymes. Thus, further efforts should be paid
for computational studies to find a truly reactive species responsible for methane
oxidation.
Acknowledgements This project was partially supported by a Grant-in-Aid for Scientific Research
(C) (No. 18K04864) from JSPS for T.Y.
References and Notes
1. Feig AL, Lippard SJ (1994) Chem Rev 94:759−805
2. Lipscomb JD (1994) Annu Rev Microbiol 48:371−399
3. Liu KE, Lippard SJ (1995) Adv Inorg Chem 42:263−289
4. Wallar BJ, Lipscomb JD (1996) Chem Rev 96:2625−2658
5. Que Jr. L, Dong Y (1996) Acc Chem Res 29:190−196
6. Valentine AM, Lippard SJ (1997) J Chem Soc Dalton Trans 3925−3931
7. Kurtz Jr. DM, (1997) J Biol Inorg Chem 2:159−167
8. Merkx M, Kopp DA, Sazinsky MH, Blazyk JL, Müller J, Lippard SJ (2001) Angew Chem
Int Ed 40:2782−2807
9. Rosenzweig AC, Frederick CA, Lippard SJ, Nordlund P (1993) Nature 366:537−543
10. Lieberman RL, Rosenzweig AC (2005) Nature 434:177−182
11. Colby J, Dalton H (1978) Biochem J 171:461−468
12. Woodland MP, Dalton H (1984) J Biol Chem 259:53−60
13. Fox BG, Froland WA, Dege JE, Lipscomb JD (1989) J Biol Chem 264:10023−10033
14. Gassner GT, Lippard SJ (1999) Biochemistry 38:12768−12785
15. Woodland MP, Patil DS, Cammack R, Dalton H (1986) Biochim Biophys Acta 873:237−242
16. Ericson A, Hedman B, Hodgson KO, Green J, Dalton H, Bentsen JG, Beer RH, Lippard SJ
(1988) J Am Chem Soc 110:2330−2332
17. Fox BG, Surerus KK, Münck E, Lipscomb JD (1988) J Biol Chem 263: 10553−10556
T. Yumura et al.
Despite increasing our understanding on the methane hydroxylation on MMO,
there still remains issues. Reliability of the computational models relies on the molecular structures developed by spectroscopic and X-ray crystallographic analyses.
Recent revisiting studies of the intermediate Q by X-ray absorption spectroscopy
(XAS) [135, 136] indicated that the previously proposed structure may be incorrect
and revised models have been proposed. However, again the new proposal by XAS
is incompatible with the resonance Raman study on the catalytic cycle of sMMO
[137]. The structure of the copper active site of pMMO is under debate as well.
While the initial X-ray crystal structure showed a dinuclear copper center, recent
analyses indicated that a mononuclear copper is involved in the active site [138].
Thus, it remains challenges for computational chemists to perform further analyses
on the follow up information.
Spectroscopic and X-ray crystallographic investigations of MMO have provided
us valuable information for theoretical studies of ours and others. However still, a
question arises as to if a major species that is visible by spectroscopy and X-ray
crystallography is really a functional species or not. We cannot eliminate a possibility that a minor speices that escapes from experimental characterizations is a
critical component for function of the enzymes. Thus, further efforts should be paid
for computational studies to find a truly reactive species responsible for methane
oxidation.
Acknowledgements This project was partially supported by a Grant-in-Aid for Scientific Research
(C) (No. 18K04864) from JSPS for T.Y.
References and Notes
1. Feig AL, Lippard SJ (1994) Chem Rev 94:759−805
2. Lipscomb JD (1994) Annu Rev Microbiol 48:371−399
3. Liu KE, Lippard SJ (1995) Adv Inorg Chem 42:263−289
4. Wallar BJ, Lipscomb JD (1996) Chem Rev 96:2625−2658
5. Que Jr. L, Dong Y (1996) Acc Chem Res 29:190−196
6. Valentine AM, Lippard SJ (1997) J Chem Soc Dalton Trans 3925−3931
7. Kurtz Jr. DM, (1997) J Biol Inorg Chem 2:159−167
8. Merkx M, Kopp DA, Sazinsky MH, Blazyk JL, Müller J, Lippard SJ (2001) Angew Chem
Int Ed 40:2782−2807
9. Rosenzweig AC, Frederick CA, Lippard SJ, Nordlund P (1993) Nature 366:537−543
10. Lieberman RL, Rosenzweig AC (2005) Nature 434:177−182
11. Colby J, Dalton H (1978) Biochem J 171:461−468
12. Woodland MP, Dalton H (1984) J Biol Chem 259:53−60
13. Fox BG, Froland WA, Dege JE, Lipscomb JD (1989) J Biol Chem 264:10023−10033
14. Gassner GT, Lippard SJ (1999) Biochemistry 38:12768−12785
15. Woodland MP, Patil DS, Cammack R, Dalton H (1986) Biochim Biophys Acta 873:237−242
16. Ericson A, Hedman B, Hodgson KO, Green J, Dalton H, Bentsen JG, Beer RH, Lippard SJ
(1988) J Am Chem Soc 110:2330−2332
17. Fox BG, Surerus KK, Münck E, Lipscomb JD (1988) J Biol Chem 263: 10553−10556