Chemistry can be defined as the study of matter and the changes it undergoes. You’ll sometimes hear it called the central science because it is the connection between physics and all the other sciences, starting with biology. 87-32-1, Name is N-Acetyl-DL-tryptophan, molecular formula is , belongs to amides-buliding-blocks compound. In a document, author is Ghorpade, Seema A., Computed Properties of C13H14N2O3.
The mechanism and high-free-energy transition state of lac repressor-lac operator interaction
Significant, otherwise-unavailable information about mechanisms and transition states (TS) of protein folding and binding is obtained from solute effects on rate constants. Here we characterize TS for lac repressor(R)-lac operator(O) binding by analyzing effects of RO-stabilizing and RO-destabilizing solutes on association (k(a)) and dissociation (k(d)) rate constants. RO-destabilizing solutes (urea, KCl) reduce k(a) comparably (urea) or more than (KCl) they increase k(d), demonstrating that they destabilize TS relative to reactants and RO, and that TS exhibits most of the Coulombic interactions between R and O. Strikingly, three solutes which stabilize RO by favoring burial/dehydration of amide oxygens and anionic phosphate oxygens all reduce k(d) without affecting k(a) significantly. The lack of stabilization of TS by these solutes indicates that O phosphates remain hydrated in TS and that TS preferentially buries aromatic carbons and amide nitrogens while leaving amide oxygens exposed. In our proposed mechanism, DNA binding-domains (DBD) of R insert in major grooves of O pre-TS, forming most Coulombic interactions of RO and burying aromatic carbons. Nucleation of hinge helices creates TS, burying sidechain amide nitrogens. Post-TS, hinge helices assemble and the DBD-hinge helix-O-DNA module docks on core repressor, partially dehydrating phosphate oxygens and tightening all interfaces to form RO.
Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data. If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 87-32-1, in my other articles. Computed Properties of C13H14N2O3.