Fatty acids are an important energy source, for they yield over twice as much energy as an equal mass of carbohydrate or protein. In humans, the primary dietary source of fatty acids is triacylglycerols. This lecture will describe the metabolism of fatty acids. The two main components of fatty acid metabolism are β oxidation and fatty acid synthesis. Upon completion of this lecture, you will understand that the fatty-acid breakdown reactions of β oxidation result in the formation of reduced cofactors and acetyl-CoA molecules, which can be further catabolized to release free energy.
Mutation cuả BRCA1, BRCA2 allele thấy trong ung thư vú, buồng trứng và prostate. Các tb có heterozygous BRCA mutations có thể mất wildtype allele, cho nên không sửa chữa được DNA, và vì thế tạo ra ung thư. Theory hiện tại về carcinogenesis cho rằng việc mất wild type allele (DNAREPAIR DEFECT) phải là một giai đoạn bắt buộc trong tiến trình ung thư. PARPs (PolyAdenosine diphosphate Ribose Polymerases) là
multifunctional enzymes trong việc sửa chữa gẫy single stranded DNA. ...
It is well established that the intracellular second messenger cADP-ribose
(cADPR) activates Ca
release from the sarcoplasmic reticulum through
ryanodine receptors. CD38 is a multifunctional enzyme involved in the for-mation of cADPR in mammals.
A cDNA encoding a novel plant type III polyketide synthase was cloned
and sequenced from the Chinese club moss Huperzia serrata(Huperzia-ceae). The deduced amino acid sequence ofHu. serratapolyketide synthase
1 showed 44–66% identity to those of other chalcone synthase superfamily
enzymes of plant origin.
Human kynurenine aminotransferase I/glutamine trans-aminase K (hKAT-I) is an important multifunctional
enzyme. This study systematically studies the substrates of
hKAT-I and reassesses the effects of pH, Tris, amino acids
anda-keto acids on the activity of the enzyme. The experi-ments were comprised of functional expression of the
hKAT-I in an insect cell/baculovirus expression system,
purification of its recombinant protein, and functional
characterization of the purified enzyme.
GlutathioneS-transferases (EC 126.96.36.199) (GSTs), are a
family of multifunctional enzymes present in all living
organisms whose main function is the detoxification of
electrophilic compounds. GSTs are considered the most
prominent detoxifying class II enzymes in helminths. We
describehere the characterizationof novel dehydroascorbate
reductase and thiol transferase activities that reside in the
human parasite Schistosoma mansoni GSTx.
Silicateins are unique enzymes of sponges (phylum Porifera) that template
and catalyze the polymerization of nanoscale silicate to siliceous skeletal
elements. These multifunctional spicules are often elaborately shaped, with
Tissue transglutaminase (TG2) is a ubiquitously expressed member of the
transglutaminase family of Ca
-dependent crosslinking enzymes. Unlike
other family members, TG2 is a multifunctional protein, which has several
other well documented enzymatic and non-enzymatic functions.
The multifunctional tissue transglutaminase 2 (TG2) has a four-domain
structure with several Ca
-regulated biochemical activities, including
transglutamylation and GTP hydrolysis. The structure of the Ca
form of the human enzyme is not known, and its Ca
-binding sites have
not been fully characterized.
The properties of theD6 desaturase/acetylenase from the
mossCeratodon purpureusand theD12 acetylenase from the
dicotCrepis alpinawere studied by expressing the encoding
genes inArabidopsis thalianaandSaccharomyces cerevisiae.
The acetylenase fromC. alpinaD12 desaturated both oleate
and linoleate with about equal efficiency. The desaturation
of oleate gave rise to 9(Z),12(E)- and 9(Z),12(Z)-octadeca-dienoates in a ratio of approximately 3 : 1.