Explain the process by which a molecule of glucose is degraded in a series of enzymatic reactions and the fate of the product formed. State the enzymes used and the products of each reaction. Describe the active site of an enzyme. Using the example o...
摘要: Examines crystal structures involving crystals of S130A thiamin phosphate synthase soaked in solutions with substrates or products. Formation of thiamin phosphate; Preparation of S130A thiamin phosphate synthase; Characterization of the enzyme-substrate complex....
We prepared S130A thiamin phosphate synthase with the intent of characterizing the enzyme-substrate complex. Surprisingly, in three thiamin phosphate synthase structures, the active site density cannot be modeled as either substrates or products. For these structures, the best fit to the electron ...
These diastereomeric products result from alternative substrate orientations within the enzyme active site (vide infra). We note that intact tRNAs acylated with 2-benzylmalonic acid (14) showed evidence of decarboxylation (indicated by a D in Fig. 3c). No evidence for decarboxylation was observed ...
It is a good model for studying enzyme kinetics and cooperativity, specifically for being able to separate those aspects of protein function through directed mutagenesis. Variant proteins were generated with mutations in four active-site residues, Phe-316, His-583, Tyr-766, and His-767. ...
Accordingly, inhibition of fatty acid synthase—a key enzyme that mediates lipogenesis—blunted the effects of Agrp neuron activation on substrate utilization. In pair-fed conditions during positive energy balance, activation of Agrp neurons improved metabolic efficiency, and increased weight gain and ...
To gain further insight into enzyme functionality, especially the effect of the active site aromatic residues, we expressed two variants with mutations in subsites on either side of the catalytic acid, subsite − 3 (W31A) and + 2 (W218A), and compared their catalytic properties on chitin ...
An atomic-resolution structure of the active γ-secretase complex bound noncovalently with a full transmembrane substrate mimetic provides a snapshot of the enzyme at or near the transition state, as it would be when poised for intramembrane proteolysis. This new structure in turn validates a ...
The structures reveal that the P-side product fragment maintains nearly all the contacts with the enzyme as seen with the P portion (distal ubiquitin) of the Lys63-linked diubiquitin substrate, with additional coordination of the Gly76 carboxylate group of the product with the active-site Zn2+...
Three PULs (MAN-PUL1,2,3) have been identified in human-associated [1] and bovine-associated strains of BtVPI-5482, which collectively, encode all the carbohydrate active enzyme (CAZyme) activities required for the saccharification of YM. Glycoside hydrolases (GHs) are a class of CAZymes ...