The in-vivo identification of the MoFe protein (FeMo cofactor) of nitrogenase in Klebsiella pneumoniae and of the Mo-storage protein in Azotobacter vinelandii via the nuclear quadrupole interaction of 99Mo(beta-)99Tc.
The expression of the MoFe protein of nitrogenase in Klebsiella pneumoniae was identified in vivo via the nuclear quadrupole interaction (NQI) of 99Mo(beta-)99Tc using perturbed angular correlations of gamma-rays. The NQI parameters were: omega approx. 360 Mrad/s and eta approx. 1. In addition, the NQI of the 'Mo-storage protein' in Azotobacter vinelandii cells which had been grown in the presence of NH4+ (13 mM), i.e. under conditions of strict repression of nitrogenase synthesis, was determined: omega approx. 190 Mrad/s, eta approx. 0.25. Under these conditions, the characteristic signal of the MoFe protein (FeMo cofactor) was absent.
Mottner
P
P
Physik Department, Technische Universität München, Garching, Germany.
Butz
T
T
Lerf
A
A
Erfkamp
J
J
Schneider
K
K
Müller
A
A
D016948:Azotobacter vinelandii / Q000378:metabolism; D007711:Klebsiella pneumoniae / Q000201:enzymology*; D008982:Molybdenum / Q000378:metabolism; D008983:Molybdoferredoxin / Q000032:analysis* / Q000302:isolation & purification; D009591:Nitrogenase / Q000737:chemistry*; D011854:Radiochemistry / Q000379:methods
D008983:Molybdoferredoxin; D008982:Molybdenum; D009591:Nitrogenase