?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F10163%2F&rft.title=DEVELOPMENT+OF+RAMAN+INSTRUMENTATION+AND+METHODOLOGIES+FORPEPTIDE+AND+PROTEIN+INVESTIGATIONS&rft.creator=Bykov%2C+Sergei+V.&rft.description=Raman+spectroscopy+is+a+tool+which+offers+numerous+advantages+for+investigating+biological+macromolecules+and+complex+systems.+The+advantages+include+but+are+not+limited+to%3A+ultrahigh+sensitivity+to+changes+in+molecular+bond+lengths+(better+then+pm+resolution)%3B+time-resolved+measurements+down+to+picoseconds+time+intervals%3B+high+selectivity+offered+by+resonance+enhancement%3B+high+adaptivity+for+investigation+of+objects+of+various+sizes+in+different+physical+state.This+thesis+is+focused+on+the+development+of+UV+resonance+Raman+spectroscopy+as+a+sensitive+and+incisive+technique+for+polypeptide+secondary+structure+determinations.+We+built+a+state-of-the-art+tunable+UV+Raman+spectrometer+for+the+193+-+270+nm+spectral+region.+This+instrument+allows+for+steady+state+and+transient+UV+Raman+measurements+of+the+conformational+transitions+of+polypeptides+and+other+macromolecules.+We+also+continued+our+search+for+new+polypeptide+backbone+conformational+markers.+For+the+first+time+we+investigated+the+dependence+of+the+C%CE%B1H2+stretching+vibrations+frequencies+on+Ramachandran+%CF%86+and+%CF%88+angles+in+glycine-based+peptides+and+showed+their+potential+for+polypeptide+conformational+analysis.We+investigated+the+conformational+preferences+of+polyglycine%2C+poly-L-lysine+and+poly-L-glutamic+acid+in+aqueous+solutions+in+their+unfolded+states.+Our+studies+indicate+that+polyglycine+in+solution+assumes+a+broad+ensemble+of+conformations+centered+around+the+Ramachandran+angles+of+the+3-1-helix.+We+explained+this+polyglycine+conformational+preference+by+favorable+electrostatic+interactions+between+adjacent+peptide+bond+carbonyl+dipoles.+Poly-L-lysine+and+poly-L-glutamic+acid+in+non-%CE%B1-helical+states+in+solution+show+a+preference+for+a+left-handed+3-1-helix+conformation+with+some+contribution+from+a+left-handed+2.5-1-helical+conformation+which+is+likely+stabilized+due+to+electrostatic+repulsion+between+charged+side+chains.+In+addition%2C+we+find+that+a+poly-L-lysine+and+poly-L-glutamic+acid+mixture+at+neutral+pH+is+~60%25+%CE%B2-sheet.We+used+time+resolved+UV+resonance+Raman+spectroscopy+to+characterize+the+spatially+resolved+(termini+vs.+center)+kinetics+of+thermal+unfolding+of+a+21+amino+acid+isotopically+labeled%2C+mainly+alanine%2C+peptide.+We+found+that+the+relaxation+rates+are+significantly+different+for+the+middle+and+terminal+peptide+bonds+and+strongly+depend+on+T-jump+temperatures.+We+explain+the+observed+kinetics+in+terms+of+different+relative+contributions+of+different+%CE%B1-helix-like+motifs+such+as+pure+%CE%B1-helices%2C+%CF%80-bulges+and+3-10+helices+to+the+observed+melting+kinetics.&rft.date=2010-06-16&rft.type=University+of+Pittsburgh+ETD&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F10163%2F5%2Fmain-file-etd-12072009-203151.pdf&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F10163%2F1%2FChapter_2_Copyright.pdf&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F10163%2F2%2FChapter_3-1_Copyright.pdf&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F10163%2F3%2FChapter_5_Copyright.pdf&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F10163%2F4%2FChepter_4-3_Copyright.pdf&rft.identifier=++Bykov%2C+Sergei+V.++(2010)+DEVELOPMENT+OF+RAMAN+INSTRUMENTATION+AND+METHODOLOGIES+FORPEPTIDE+AND+PROTEIN+INVESTIGATIONS.++Doctoral+Dissertation%2C+University+of+Pittsburgh.++++(Unpublished)++