We thus define the final weighting function as: w ( n ) = 1 - ∑ k = 1 N gci g ( n - T k ) (5).
The average value of the critical interface crack propagation energy Gci at the porous Ag/BaTiO3 interface ranges between 4.5 and 6.6 J/m2 while the porosity decreases from 11% to 7%.
The second best supported model (with a difference of less than two units in its AIC from the first model) was the model that included spider size, % UV, Gci and the double interactions between spider size and %UV, spider size and Gci, and %UV and Gci.
We also investigated the specificity of Gci for the γ- and δ-lactones.
Because KDG is the product of the reaction catalyzed by Gci, the proximity of these genes is not surprising.
In Figure 3, the green line shows the progress of the reaction when Gci is added to γ-lactone produced in the absence of A9CEQ7; the blue line shows the progress of the reaction when Gci is added to a reaction mixture containing the δ-lactone.
This pathway is initiated by a uronate dehydrogenase that oxidizes d-galacturonate to d-galactaro-1,5-lactone (δ-galactarolactone); a lactone isomerase (GLI; UniProt entry A9CEQ7; locus tag Atu3138) then converts δ-galactarolactone to γ-galactarolactone, the substrate for Gci.
Following this isomerization, Gci catalyzes the ring opening reaction of the γ-lactone to produce KDG that undergoes dehydration and decarboxylation to form α-ketoglutarate semialdehyde, which is oxidized to α-ketoglutarate, an intermediate in the citric acid cycle.
Also, because Gci catalyzes the ring opening reaction of d-galactaro-γ-lactone to KDG, no need for a lactonase is apparent, i.e., a reaction similar to that catalyzed by LigI.
However, on the basis of the proximity of the genes encoding A9CEQ7 and Gci and the structural similarity between PDC and d-galactaro-δ-lactone, we hypothesized that A9CEQ7 catalyzes the δ- to γ-lactone isomerization and therefore is a "missing" enzyme in this pathway.
