Regulation of Alpha-Aminoadipate Reductase From Penicillium Chrysogenum in Relation to the Flux From Alpha-Aminoadipate Into Penicillin Biosynthesis

Can J Microbiol. 1992 Aug;38(8):758-63. doi: 10.1139/m92-123.

Abstract

The activity and regulation of alpha-aminoadipate reductase in three Penicillium chrysogenum strains (Q176, D6/1014/A, and P2), producing different amounts of penicillin, were studied. The enzyme exhibited decreasing affinity for alpha-aminoadipate with increasing capacity of the respective strain to produce penicillin. The enzyme from all three strains was inhibited by L-lysine, and the enzyme from the lowest producer, Q176, was least sensitive. Between pH 7.5 and 6.5, inhibition of alpha-aminoadipate reductase by L-lysine was pH dependent, being more pronounced at lower pH. The highest producer strain, P2, displayed the lowest alpha-aminoadipate reductase activity at pH 7.0. In Q176, the addition of 0.5-1 mM of exogenous lysine stimulated penicillin formation, whereas the same concentration was ineffective or inhibitory with strains D6/1014/A and P2. The addition of higher (up to 5 mM) lysine concentrations inhibited penicillin production in all three strains. In mutants of P. chrysogenum D6/1014/A, selected for resistance to 20 mM alpha-aminoadipate, highest penicillin production was observed in those strains whose alpha-aminoadipate reductase was most strongly inhibited by L-lysine. The results support the conclusion that the in vivo activity of alpha-aminoadipate reductase from superior penicillin producer strains of P. chrysogenum is more strongly inhibited by lysine, and that this is related to their ability to accumulate increased amounts of alpha-aminoadipate, and hence penicillin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldehyde Oxidoreductases / chemistry
  • Aldehyde Oxidoreductases / metabolism*
  • L-Aminoadipate-Semialdehyde Dehydrogenase
  • Lysine / pharmacology
  • Penicillin Resistance
  • Penicillins / biosynthesis*
  • Penicillium chrysogenum / enzymology*

Substances

  • Penicillins
  • Aldehyde Oxidoreductases
  • L-Aminoadipate-Semialdehyde Dehydrogenase
  • Lysine