scissile การใช้

• This mechanism involves attack of a water molecule at the scissile peptide linkage of the substrate.
• The abstracted proton is then removed from the glutamate by the nitrogen of the scissile amide.
• The main difference arises in the location of the carbonyl oxygen atom of the scissile peptide bond.
• Nitrile in the position of the scissile bond of the peptidic substrate that is important for high potency.
• The close approach of the A9 and scissile phosphates requires the presence of a high concentration of positive charge.
• It was recently shown that a Mg2 + ion interacts with the 2-OH of the scissile nucleotide.
• In the active site, a water molecule is scissile carbon while the glutamate simultaneously abstracts a proton from the water molecule.
• Rearrangement of this intermediate leads to protonation of the scissile amide which results in the splitting of the substrate peptide into two product peptides.
• This metal is thought to act as a lewis acid which activate the 2-OH for a nucleophilic attack on the scissile phosphate.
• The active inhibitory site containing the scissile bond is located in the loop between beta-strands 4 and 5 in STI and ETI.
• Because of the specificity of the active site, OmpT does not act on peptides with a negatively charged residue adjacent to the scissile bond.
• In order for the amide product to be released from the active site, the scissile amide must abstract a second proton from the coordinated water molecule.
• This binding site is away from the scissile bond ( cleavage site ) and thus does not explain the involvement of the Pb 2 + in the catalysis.
• When LPS is not present, the peptide binds too deeply within the active site, and the water cannot reach the carbonyl for its nucleophilic attack of the scissile bond.
• In her study, published in September 2016, Hammes-Schiffer contributed towards discovering the effects of the active site of the magnesium ion in the Scissile Phosphate cofactor complex.
• This second binding site explains how Pb 2 + could facilitate catalysis by abstracting the 2-OH proton and prepare it for an in-line nucleophillic attack on the scissile phosphate.
• Moreover, the A9 and scissile phosphates are observed to be 4.3 ?apart, consistent with the idea that, when modified, these phosphates could bind a single thiophilic metal ion.
• As the bond between the scissile phosphorus and the 5'- O leaving group begins to break, a proton is supplied from the ribose of G8, which then likely reprotonates at the expense of a water molecule observed to hydrogen bond to it in the crystal structure.
• The Mg 2 + ion on the right ( "'Figure 3 "') interacts with negatively charged oxygens of the alpha ( ? ), beta ( ? ) and gamma ( ? ) phosphates to align the scissile bond for the primer to attack.
• The key features of Kex2 and Furin are a subtilisin-related catalytic domain, a specificity pocket that requires the amino acid amino terminal to the scissile bond to be arginine for rapid acylation, and a P-domain carboxy-terminal to the subtilisin domain, which is required for biosynthesis.