The biosynthesis of steroids and triterpenoids

The rate of turnover in a metabolic pathway, otherwise known as the metabolic flux , is regulated based on the stoichiometric reaction model, the utilization rate of metabolites, and the translocation pace of molecules across the lipid bilayer . [20] The regulation methods are based on experiments involving 13C-labeling , which is then analyzed by Nuclear Magnetic Resonance (NMR) or gas chromatography-mass spectrometry (GC-MS) -derived mass compositions. The aforementioned techniques synthesize a statistical interpretation of mass distribution in proteinogenic amino acids to the catalytic activities of enzymes in a cell. [21]

In bacteria, the enzyme glutamate 5-kinase initiates the biosynthesis of proline by transferring a phosphate group from ATP onto glutamate. The next reaction is catalyzed by the enzyme pyrroline-5-carboxylate synthase (P5CS), which catalyzes the reduction of the ϒ-carboxyl group of L-glutamate 5-phosphate. This results in the formation of glutamate semialdehyde, which spontaneously cyclizes to pyrroline-5-carboxylate. Pyrroline-5-carboxylate is further reduced by the enzyme pyrroline-5-carboxylate reductase (P5CR) to yield a proline amino acid. [28]

The conversion of HMG-CoA to mevalonate by HMG-CoA reductase is the rate-limiting step of cholesterol biosynthesis and is under strict regulatory control (see Figure 1 ). HMGR is the target of compounds that are effective in lowering serum cholesterol levels. Human HMG-CoA reductase consists of a single polypeptide chain of 888 amino acids. The amino-terminal residues are membrane bound and reside in the endoplasmic reticulum membrane, while the catalytic site of the protein resides in its cytoplasmic, soluble carboxy-terminal portion. A linker region connects the two portions of the protein.

The biosynthesis of steroids and triterpenoids

the biosynthesis of steroids and triterpenoids

Media:

the biosynthesis of steroids and triterpenoidsthe biosynthesis of steroids and triterpenoidsthe biosynthesis of steroids and triterpenoidsthe biosynthesis of steroids and triterpenoidsthe biosynthesis of steroids and triterpenoids

http://buy-steroids.org