Summary
In modelling enzyme synthesis the Q-function has been generalized to describe ordinary induction and repression as well as mixed induction-repression. The practical use of the Q-function as found in the literature was considered, especially the implications of applying fractional exponents.
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Abbreviations
- Co :
-
Binding constant of uncomplexed repressor protein to operator site
- Ci :
-
Binding constant of REi to operator site
- E:
-
Effector
- Enz:
-
Enzyme
- i:
-
Index (number of effector molecules)
- k1 :
-
rate constant
- k2 :
-
rate constant
- Ki :
-
Formation constant of repressor protein with i effector molecules
- mRNA:
-
Messenger ribonucleic acid
- n:
-
Index (number of effector molecules)
- O:
-
Operator site
- [O]t :
-
Total concentration of operator sites
- OR:
-
Uncomplexed repressor protein bound to operator site
- OREi :
-
Repressor complexed with i effector molecules and bound to operator site
- p:
-
The maximum number of effector molecules bound to repressor protein
- Q:
-
The fraction of operons which can be transcripted
- R:
-
Repressor protein
- REi :
-
Repressor protein complexed with i effector molecules
- [R]t :
-
Total concentration of repressor protein
- X:
-
Biomass
- []:
-
Concentration
References
Aarons LJ, Gray BF (1978) On the effect of a small parameter and the possibility of limit cycle behaviour in a negatively inductive control system. J Theor Biol 50:501–505
Dedem G van, Moo-Young M (1973) Cell growth and extracellular enzyme synthesis in fermentations. Biotechnol Bioeng 15: 419–439
Gondo S, Venkatasubramanian K, Vieth WR, Constantinides A (1978) Modelling the role of cyclic AMP in catabolite repression of inducible enzyme biosynthesis in microbial cells. Biotechnol Bioeng 20:1797–1815
Hippel PH von (1979) On the interactions of genome-regulatory proteins with DNA. In: Rosenthal S, Bielka H, Coutelle Ch, Zimmer Ch (eds) FEBS 12 Meeting Dresden, vol 51, Gene Function. Pergamon Press, New York, p 51
Imanaka T, Aiba S (1977) A kinetic model of catabolite repression in the dual control mechanism in microorganisms. Biotechnol Bioeng 19:757–764
Reuser AJJ, Post MA (1972) The induction of a C4-dicarboxylic acid anion translocator in Azotobacter vinelandii. FEBS Lett 21:145–148
Toda K (1976) Dual control of invertase biosynthesis in chemostat culture. Biotechnol Bioeng 18:1117–1124
Toda K, Takeuchi T, Sano H (1979) Growth rate dependence of enzyme synthesis in chemostat cultures: α-amylase, β-galactosidase, acid phosphate, and β-fructosidase. J Chem Tech Biotechnol 29:747–755
Toda K, Yabe I (1979) Mathematical model of cell growth and phosphatase biosynthesis in Saccharomyces carlsbergensis under phosphate limitation. Biotechnol Bioeng 21:487–502
Yagil G, Yagil E (1971) On the relation between effector concentration and the rate of induced enzyme synthesis. Biophysical J 11:11–27
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Nielsen, H.K., Martiny, S.C. Mathematical modelling of enzyme synthesis during fermentations: The Q-functions. European J. Appl. Microbiol. Biotechnol. 13, 67–70 (1981). https://doi.org/10.1007/BF00499690
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DOI: https://doi.org/10.1007/BF00499690