Salt dependence, kinetic properties and catalytic mechanism of 
N-formylmethanofuran:tetrahydromethanopterin formyltransferase from the extreme 
thermophile Methanopyrus kandleri

Breitung, Jürgen; Börner, Gerhard; Scholz, Sabine; Linder, Dietmar; Stetter, Karl O.; Thauer, Rudolf K.

doi:10.1111/j.1432-1033.1992.tb17502.x

Item

ITEM ACTIONSEXPORT

Add to Basket

Local TagsRelease HistoryDetailsSummary

Released

Journal Article

Salt dependence, kinetic properties and catalytic mechanism of N-formylmethanofuran:tetrahydromethanopterin formyltransferase from the extreme thermophile Methanopyrus kandleri

MPS-Authors

Breitung, Jürgen
Laboratorium für Mikrobiologie, Fachbereich Biologie, Philipps- Universität, Marburg;
Department of Biochemistry, Alumni, Max Planck Institute for Terrestrial Microbiology, Max Planck Society;

Börner, Gerhard
Laboratorium für Mikrobiologie, Fachbereich Biologie, Philipps- Universität, Marburg;
Department of Biochemistry, Alumni, Max Planck Institute for Terrestrial Microbiology, Max Planck Society;

Scholz, Sabine
Laboratorium für Mikrobiologie, Fachbereich Biologie, Philipps- Universität, Marburg;
Department of Biochemistry, Alumni, Max Planck Institute for Terrestrial Microbiology, Max Planck Society;

/persons/resource/persons254760

Thauer, Rudolf K.
Laboratorium für Mikrobiologie, Fachbereich Biologie, Philipps- Universität, Marburg;
Department of Biochemistry, Alumni, Max Planck Institute for Terrestrial Microbiology, Max Planck Society;

External Resource

https://doi.org/10.1111/j.1432-1033.1992.tb17502.x
(Publisher version)

Fulltext (restricted access)

There are currently no full texts shared for your IP range.

Fulltext (public)

There are no public fulltexts stored in PuRe

Supplementary Material (public)

There is no public supplementary material available

Citation

Breitung, J., Börner, G., Scholz, S., Linder, D., Stetter, K. O., & Thauer, R. K. (1992). Salt dependence, kinetic properties and catalytic mechanism of N-formylmethanofuran:tetrahydromethanopterin formyltransferase from the extreme thermophile Methanopyrus kandleri. European Journal of Biochemistry, 210(3), 971-981. doi:10.1111/j.1432-1033.1992.tb17502.x.

Cite as: https://hdl.handle.net/21.11116/0000-000F-9116-4

Abstract

N-Formylmethanofuran(CHO-MFR): tetrahydromethanopterin(H4MPT) formyltransferase (for-myltransferase) from the extremely thermophilic Methanopyrus kandleri was purified over 100-fold to apparent homogeneity with a 54% yield. The monomeric enzyme had an apparent molecular mass of 35 kDa. The N-terminal amino acid sequence of the polypeptide was determined. The formyltransferase was found to be absolutely dependent on the presence of phosphate or sulfate salts for activity. The ability of salts to activate the enzyme decreased in the order K2HPO4 > (NH4)2SO4 > K2SO4 > Na2SO4 > Na2HPO4. The salts KCl, NaCl and NH4Cl did not activate the enzyme. The dependence of activity on salt concentration showed a sigmoidal curve. For half-maximal activity, 1 M K2HPO4 and 1.2 M (NH4)2SO4 were required. A detailed kinetic analysis revcaled that phosphates and sulfates both affected the Vmax rather than the Km for CHO-MFR and H4MPT. At the optimal salt concentration and at 65°C, the Vmax was 2700 U/mg (1 U = 1 ?mol/min), the Km for CHO-MFR was 50 ?M and the Km for H4MPT was 100 ?M. At 90°C, the temperature optimum of the enzyme, the Vmax was about 2.5-fold higher than at 65°C. Thermostability as well as activity of formyltransferase was dramatically increased in the presence of salts, 1.5 M being required for optimal stabilization. The efficiency of salts in protecting formyltransferase from heat inactivation at 90°C decreased in the order K2HPO4= (NH4)2SO4? KCI = NH4Cl = NaCl ? Na2SO4 > Na2HPO4. The catalytic mechanism of formyltransferase was determined to be of the ternary-complex type. The properties of the enzyme from M. kandleri are compared with those of formyltransferase from Methanobacterium thermoautotrophicum, Methanosarcina barkeri and Archaeoglobus fulgidus.