02523nas a2200169   4500008004100000022001400041245012800055210006900183260000800252300001400260490000700274520188300281100002202164700001502186700002402201856012802225       2023                        eng d  a0006-296000aElectrostatic modulation of intramolecular and intermolecular interactions during the formation of an amyloid-like assembly0 aElectrostatic modulation of intramolecular and intermolecular in  cMAY  a1890-19050 v623 a<p>
	The mechanism of protein aggregation can be broadly viewedas ashift from the native-state stabilizing intramolecular to the aggregated-phasesustaining intermolecular interactions. Understanding the role ofelectrostatic forces on the extent of modulation of this switch hasrecently evolved as a topic of monumental significance as proteinaggregation has lately been connected to charge modifications of anaging proteome. To decipher the distinctive role of electrostaticforces on the extremely complicated phase separation landscape, weopted for a combined in vitro-in silico approach to ascertainthe structure-dynamics-stability-aggregabilityrelationship of the functional tandem RRM domains of the ALS-relatedprotein TDP-43 (TDP-43(tRRM)), under a bivariate solutioncondition in terms of pH and salt concentration. Under acidic pH conditions,the native TDP-43(tRRM) protein creates an aggregation-proneentropically favorable partially unfolded conformational landscapedue to enthalpic destabilization caused by the protonation of theburied ionizable residues and consequent overwhelming fluctuationsof selective segments of the sequence leading to anti-correlated movementsof the two domains of the protein. The evolved fluffy ensemble witha comparatively exposed backbone then easily interacts with incomingprotein molecules in the presence of salt via typical amyloid-aggregate-likeintermolecular backbone hydrogen bonds with a considerable contributionoriginating from the dispersion forces. Subsequent exposure to excesssalt at low pH conditions expedites the aggregation process via anelectrostatic screening mechanism where salt shows preferential bindingto the positively charged side chain. The applied target observable-specificapproach complementarity unveils the hidden information landscapeof an otherwise complex process with unquestionable conviction.</p>
1 aPillai, Meenakshi1 aDas, Atanu1 aJha, Santosh, Kumar  uhttps://library.ncl.res.in/content/electrostatic-modulation-intramolecular-and-intermolecular-interactions-during-formation