Synthesis of Polypeptides Using Difunctional InitiatorsJulie KlussRese - PDF document

Synthesis of Polypeptides Using Difunctional InitiatorsJulie KlussResearch Experiences for Teachers (RET)Mentor: Dr. Krystyna BrzezinskaDeming Research GroupSponsor: MRL Program, NSF IntroductionGoal of Research: Synthesis of polypeptides using difunctionalinitiatorsWhat is an initiatorIt is a molecule which combines with a monomer+ ~ IntroductionFocus Questions•First step:How effective are certain initiators in activating living polymerization?•Next step:Are the initiators difunctional+MI~+I~MM~I~M~ H O Ni (depe) MethodsExperimental Objectives: •Test and analyze effectivenessof initiators.•Introduce “weak link” to prove initiators (future)Materials:3 sample initiators•Monomer (Glu-NCA)•Solvents (THF, DMF, ethyl ether)Drybox Polymerization of Glu-NCAM*I~ HO R O O NH O NNi )6 NH2 NH n O R X H n O O CC(CH Init. room tempTHF Init = (depe) (depe) Init 1 = X: Init 2 = Init 3 = depe = 1,2-bis(diethylphosphino) ethaneR' = -CHCH(CHR = -CH Init 4 = , varying initiator concentration.) Synthesis of Polypeptide 1.In drybox,in ethyl ether and dry polymer.Drybox dissolvedin DMF, injected columns.2. Large molecules move faster than 3. Polymer solution moves from columns to scattering 4. Detector sends data to computerprogram, which plots curve and prints report. Results Initiator 1y = -3E+06x + 109643 = 0.92932000040000600008000010000012000000.0050.010.0150.020.025Initiator 1 (mmol)Mn (GPC) (mmol) (GPC) PDI 0.00365 NHO R O O NH O Ni NH2 NH n O R H n O O 48 hrsroom temp THF (depe) (depe) Initiator Resultsnvs Amount of Initiator 10000012000014000000.0050.010.0150.020.025Initiator (mmol)Mn (GPC) Initiator 1 Initiator 2 Initiator 3 Linear (Initiator 1) Linear (Initiator 2) Linear (Initiator 3) ConclusionsDespite different core structures, all initiators effectively polymerizedGlu-NCA.Future workProve of initiator:NH2 NH n NH O O R H n O O CH CH OsO, THF H n O O R' = -CHR = -CH n by GPC Potential application•Use difunctional initiatorsto prepare ABA block ICreate polypeptides with predetermined propertiesand sizes. Fume hood Personal Reflections•Scientific research is an inquiry-based and data-driven process of discovery. questions and answers are not provided beforehand.Scientists are perseveringFormal research is a long-term, sometimes tedious, carefully documented process.•Formal research integrates other academic disciplines. communication, & literacy.