reverett123
08-01-2008, 05:46 PM
Perhaps mucuna's action is not the result of the extra Ldoa it contains but is its unknown enzymes. It has the ability to make Ldopa, presumably from tyrosine, in its natural state. If we ingest that enzyme and have enough tyrosine in our systems, might it not go to work converting same?
1: Biotechnol Bioeng. 1989 Jun 20;34(2):214-22.
Kinetic aspects of the bioconversion of L-tyrosine into L-DOPA by cells of Mucuna
pruriensL. Entrapped in different matrices.
Pras N, Hesselink PG, Ten Tusscher J, Malingré TM.
Department of Pharmacognosy, University of Groningen, A. Deusinglaan 2, 9713 AW
Groningen, The Netherlands.
Plant cells of Mucuna pruriens L. entrapped In calcium alginate, calcium
pectinate, agarose, or gelatine were able to convert L-tyrosine to L-DOPA, which
was released Into the medium. Michaelis-Menten kinetics could be applied on the
entrapped cells, based on the measurement of initial rates of L-DOPA production.
The calculated apparent affinity constants were comparable with the affinity
constants obtained with enzyme preparations. Comparison of the apparent maximum
rate of bioconversion of the entrapped cells and the maximum rate of
bioconversion of a derived cell homogenate indicated that the systems were not
operating optimally. Measurement of the effective diffusion coefficients of
L-tyrosine pointed out that this substrate could diffuse freely into the
matrices. From the initial rates of bioconversion and the effective diffusion
coefficients, the observable modulus was calculated for each system. The obtained
values confirmed that the diffusional supply rate of L-tyrosine was not the
limiting factor. For oxygen, which was utilized for byconversion as well as for
cell respiration, the calculated observable moduli was directed toward strong
oxygen transfer limitations. The values found for the oxygen consumption
indicated that the entrapped cells remained partly or totally viable in the four
matrices tested. Based on the highest viability and the highest rates of
bioconversion, it was concluded that alginate-entrapped cells of M. pruriens
formed the most suitable biocatalytic system for the production of L-DOPA from
L-tyrosinre.
PMID: 18588095 [PubMed - in process]
1: Biotechnol Bioeng. 1989 Jun 20;34(2):214-22.
Kinetic aspects of the bioconversion of L-tyrosine into L-DOPA by cells of Mucuna
pruriensL. Entrapped in different matrices.
Pras N, Hesselink PG, Ten Tusscher J, Malingré TM.
Department of Pharmacognosy, University of Groningen, A. Deusinglaan 2, 9713 AW
Groningen, The Netherlands.
Plant cells of Mucuna pruriens L. entrapped In calcium alginate, calcium
pectinate, agarose, or gelatine were able to convert L-tyrosine to L-DOPA, which
was released Into the medium. Michaelis-Menten kinetics could be applied on the
entrapped cells, based on the measurement of initial rates of L-DOPA production.
The calculated apparent affinity constants were comparable with the affinity
constants obtained with enzyme preparations. Comparison of the apparent maximum
rate of bioconversion of the entrapped cells and the maximum rate of
bioconversion of a derived cell homogenate indicated that the systems were not
operating optimally. Measurement of the effective diffusion coefficients of
L-tyrosine pointed out that this substrate could diffuse freely into the
matrices. From the initial rates of bioconversion and the effective diffusion
coefficients, the observable modulus was calculated for each system. The obtained
values confirmed that the diffusional supply rate of L-tyrosine was not the
limiting factor. For oxygen, which was utilized for byconversion as well as for
cell respiration, the calculated observable moduli was directed toward strong
oxygen transfer limitations. The values found for the oxygen consumption
indicated that the entrapped cells remained partly or totally viable in the four
matrices tested. Based on the highest viability and the highest rates of
bioconversion, it was concluded that alginate-entrapped cells of M. pruriens
formed the most suitable biocatalytic system for the production of L-DOPA from
L-tyrosinre.
PMID: 18588095 [PubMed - in process]