Organic syntheses and characterizations of multifunctional enzyme inhibitors in mevalonate pathway
甲羥戊酸途徑中酶的多功能抑製劑的合成及表徵
Student thesis: Master's Thesis
Author(s)
Detail(s)
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Award date | 15 Jul 2008 |
Link(s)
Permanent Link | https://scholars.cityu.edu.hk/en/theses/theses(ff5afdbd-37cb-48c3-ac20-9a867fe02d65).html |
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Other link(s) | Links |
Abstract
According to official reports, cardiovascular disease and cancer are major causes of death in
many countries. Cardiovascular disease is closely related with high cholesterol level, therefore,
inactivation of enzymes involved in cholesterol biosynthesis is one major method for treating
cardiovascular disease. Mevalonate pathway is a main pathway responsible for cholesterol
biosynthesis, which include 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase,
mevalonate kinase (MVK), phosphomevalonate kinase (PMK), mevalonate 5-diphosphate
decarboxylase (MDD), farnesyl pyrophosphate synthase (FPPS) and several other enzymes. The
mevalonate pathway is a drug target for chemotherapy of cardiovascular disease at present, and is
a promising target for the development of anticancer and antimicrobial agents.
Because it is difficult to inhibit an enzyme completely (particularly with a reversible inhibitor),
inhibition of two consecutive enzymes in a pathway using a combined drug treatment can block
the pathway much more effectively than a single inhibitory drug therapy. Therefore, drug
combination has been used in clinical treatment of various diseases, and sequential blocking of
two enzymes in a metabolic or biosynthetic pathway is one strategy for enhancing treatment.
In this thesis, our work is mainly composed of three parts. The first part is the expression and
purification of three enzymes, which are all ATP-dependent, in the mevalonate pathway: MVK,
PMK and MDD. These enzymes are all related with the regulation of cholesterol biosynthesis in
cells and may be promising targets for controlling the downstream product biosynthesis in the
mevalonate pathway. The second part is syntheses of bifunctional or multifunctional enzyme
inhibitors for the enzymes listed above. We developed new type of inhibitors by adding the
naturally existing amino acid and geranyl group as the functional groups into the biphosphate. It
is possible that there are strong interactions between the amino acids in the inhibitors and the
enzymes. Geranyl pyrophosphate has been reported as feed back inhibitor of mevalonate
pathway. The last part is the activity tests of the inhibitors for the three enzymes. The results
indicate that several inhibitors show strong inhibition activities and may be useful compounds for
further development for treating cardiovascular disease and cancer. Some of the inhibitors show
inhibition of more than one enzyme, and this type of molecules offer us a new example of a
single inhibitor blocking two sequential steps simultaneously in the mevalonate pathway.
In conclusion, this thesis describes the development of multifunctional inhibitors in the
mevalonate pathway. A series of inhibitors were synthesized and characterized, and some of them
were found to be multifunctional enzyme inhibitors in mevalonate pathway. This study provides
us useful information for the development of new drugs for the treatment of cardiovascular
disease and cancer.
- Enzymes, Mevalonic acid