1.. . ,, . -.. ... .... :- .' .- !. ~ . +1 .. . . 1.; b- " ,w .. as .". . 3,: 1- . Ur! .'>u w .: ;,",r ,w ' .x' wit. ." V 1,: -,- ;.. a mm '.'171',!- 1-..1 'fr'. "1 f uni: t,:,, ~ { ,., " 1 mmja- :1 2', "~ i 135.15, ;, ,' r 4- a - , T? Hrs; ,3. . , . *1 . 139: ' 5 ,3 H? <1 7 -' a' 5 ~' " {a i. _. 3,. 131 - ' [9.1 . ,2}: - - w)? .I 1,, i . 1.75,};- .51, 11%.; . . . : ( 41; >1 1 ,/ -., W 1 . ' 15:5 2:. 5:51.. 1.1. 'i1ji;, '. .. . 1 1 : .. .f- 1 1 . .. 11:1 1,": . 33 / -.' , . _ .1 ,. , "F331;? .! 1. ._;. . . 5g; .. "w 'v . $4 . , 3.9(11 em . 5.9 '5. Z5157 5% 351' . 5 1 b 33:33:44."? 2112 '13???:*19;&.~4sa 5" . .1 I??? i a 417 .5 1' if. $1341: ' A ' 5. 1* . '1? . 5 .l 4: L____ 11s), ("111 :5; _ :5; , S 2007 PROGRAM 1,2; 3.3% ThlrtyThlrd Annual 2 . . -_. .3 4.; "r: . '4 ' '-. ~ .4 1 w a. 8:30 am. Registration and Continental Breakfast, of enzymatic transition states are not yet possible. Transition 4"; J Naff SympOSlum on fr}:- 11;: . Singletary Center for the Arts state structure can be probed by kinetic isotope effects cou if. {32}; 1 ; :3"? pled to quantum chemical structures of proposed transition 1,171.911 _ 2 $5.75", '_'j;.f-,,z-:1; 9:10 am. Welcome by Dr. Charles A. Staben, Associate states. An accurate transition state structure provides a blue- {27; C hem lstry ': L" VP for Research, University of Kentucky - print for the design of transition state analogues. Chemically 1-~T"fim;...j ; 1,3} ,;f;,j:; Singletary Center for the Arts, Recital Hall stable mimics of enzymatic transition states convert the en- 53:31:14)} - 1 1'?ng . fir-'11. 1 ergy of catalysis into binding energy. Thus, transition state 71 g; 2:14;}: 1 & i133, _ .3 3 9:20 am. Introductory Remarks - Dr. Steven W. Yates, analogues have the potential to bind to target enzymes mil- View, 7'51 igligxlf31; _ 3; Chairman, Department of Chemistry, Univer lions of times more tightly than the substrates. Our drug de- fe; 5:51 M lecu la r A? "15%; sity of Kentucky sign program, bUIlt around tranSItlon state theory, is now pro- '~. L, 1354" 2.21;; O 1?,22142; 41:. ducing powerful transition state analogues for several targets 151; _ "5'! i" -' 9:30 am. Dr. John A. Gerlt, University of Illinois at Ur- with promise for treatment of T-cell leukemia, B-cell leukemia, wait; if; BIOIOgy i' ".1 .1 , 5:351.. bana-Champaign autoimmune diseases, prostate cancer, head and neck can a??? g k, "Discovering and Predicting New Enzymes in cer, and malaria. Bacterial antibiotics are also being devel- - 1, {i3igg;sg;: , the Enolase Superfamily" oped in this program. Two compounds, Immucillin-H and ,,L~<;-E~;;f 2;", as,j , _ _ DADMe-lmmucillin-H are in clinical trials for leukemia and :L,j:}.wt<-ei . it *1! Many members of the mechanlstlcally diverse enolase autoimmune diseases. ;,.;' . 1! . ,1 . .1 j, 3% superfamily have unknown functions. We are using two 11.3~.,c;f"-=,~ ' / 5%,; 1:, strategies to assign them: 1) experimental screening of librar 2:40 pm. Break (Refreshments Available) , 4:..1117? A: ,. , "f 1733;, ies of potential substrates, and 2) in silico prediction using 521.3:129'1': ,_ 1;; 5 >6; homology models and docking of libraries of potential sub- 3:00 pm. Dr. JoAnne Stubbe, Massachusetts Institute of a.~f_: ,- " 1 i. _- 1 4: Us strates. Using the rst strategy, we recently published the Technology l . g :7; assignments of Lfuconate dehydratase and D-tartrate dehy- "Unnatural Amino Acids: Tools to Investigate - ., . ' 1'5 . .1 ' {R1131}; dratase functions. We now have discovered that members of Radical Propagation in Class I Ribonucleotide x59: :31; f i_ 5. , . 'f =3 another orthologous group catalyze the dehydration of both Reductase" Raf-1'23 : 71., 1:5; '. :12; '4': galactarate and L-talarate as well as their interconversion by . . %"t= as '55 inf; . epimerization. Using the in silico strategy, we predicted that R'POWC'BOt'de reductases (RNRS) _ catalyze the, thus ,3 31 established in the memory of 5:41: members of a divergent orthologous group would catalyze the conversmn 0? nucleotides t0 deoxynucleotldes In all organisms 37.12;}? g _,;,.3-3 A S N ff 2} a {Hat racemization of Nsuccinyl Arg and N-succinyl Lys. We ex- Plat/"19 an essential role In DNA replication and repair. Class I .1 33.1.3972; 1 nna ' a 11:...1121 551};[5 perimentally veried these predictions and solved the structure RNRS are composed 0f tW0 homodimeric subunits: R1 (0(2) 1- vrs 5 " _'~:;s;.:; of this N-succinylamino acid racemase. The predicted and and R2(BZ). R2 contains the diiron tyrosyl radical (Y-) _<-:s.....,';;s.-.1 21.:1___. .ri;j".1.:"j-::l55. 1.}! experimental structures of liganded complexes are in excellent cofactor essential for activity. R1 contains the active site . 2.. 7:3ng Enzyme Catalysis and 3 .*=' _' agreement. Thus, computational approaches provide a viable Where nucleotide reduction Occurs. An unresolved EC _ 1 . .s; strategy for successfully assigning function to members of the mechanistic issue is how the Y' in R2 generates a transient Ln : :1 s 4;: MGChan'sms 15 . {if enolase superfamiliy as well as other enzymes discovered in thiyl radical on R1 to initiate the reduction process. This as 8 1%,; jigw it; 1-,. 1;" -.', genome projects. Supported by GM-71790. initiation is thought to occur over a 35 A distance and involve 46)- > Q ".j ,,.f 2,1 , E 5;: 1 53 _ generation of aromatic amino acid radical intermediates. g x (CI) in; 1; SPEAKERS 41f I 51-:;;.-;.;; 10140 a.m. Break (Refreshments Available) Experiments using unnatural amino acids ((F)ntyrosines (n = (D g o ligjil if 1.7: 7?? . _ 2, 3, 4), 3-hydroxytyrosine, nitrotyrosine, and benzophenone) _c 4.. 8 3117;}?TT'T511 Si.ve;151.1j-j=':' 11:00 am. Poster Session, Room CP-137, Chemistry- in position 356 of R2 have been carried out. These studies 0 g q j: 51", John A Ger 1: 711,6?"1"i;.3::z~.=f PhYSICS 3de provide direct evidence for interrnediacy of a Y356- on the 5 :C >_ ,1: 5 ' .{g _ propagation pathway. We have recently been able to place ,,_, B x ;:.j"v"~j;5;;,.;. .21.; Vern L. Schramm .15., V;;.,-,<1,7-1;_;.: 17-300 P-m- Buffet Lunch, Alumni Rouse [Please return unnatural amino acids in the R1 subunit. These studies have C it! xi} JoAnne Stubbe fies; 15? registration card by April 6, 2007 for reserva- demonstrated the importance of Y730 and Y731 within R1 for GE) 3? g ame"? 1 154 -., . 33.2: if 051 the radical propagaton process and the substrate/effector t Q *5, ,t?xs;\'ti_,i },.~?/ .; _ _ conformational gating of this process. Our studies provide to a.) r: bjvETZFE; 752 . . iii-57 153 .s 1330 P-m- Dr. VernL. Schramm, Albert Einstein College direct evidence for hole migration through amino acid radical 3 E '>_< "i'g, Friday, Apr" 13 2007 g}: C: 543,7 '31:. 0f Medlcrne intermediates over a long distance. D 3 3 _tl_i:f.ti}:l, . ,3 at; ;.:}j<',f;;3'7 "Drugs for Cancer and Malaria from Transition 93. . Vii-1 1.1:; f" :31?) >- State Analysis" 4:10 pm. Closing Remarks - Dr. Anne-Frances Miller, . 71 2.75.1.7. .2, - 17's. -. 'vfiii . _ _ _ .. Department of Chemistry, University of Ken- 3 -Lv;.lg,ji.'~~.i.- 1' Department Of ChemIStry : -3 A thermodynamic.descrlptlon of the enzymatic transition tucky o 1:1,:11-331531 ~-_;.;;1 UanerSIty of Kentucky 21-ij _ {xi-1 ,v' state is the bond-Vibrational instant of bond breaking. With a 1, :...;;~.s*.*.}_._;~jf-l,: . sag a .1 .- lifetime less than a single bond vibration, direct observations (http://www.chem.uky.edu/seminarslnaff/welcome.html) a _'}'.;"1-."/ 1 Lexmgton, KY 40506'0055 .1134. 33;? if f: .. ,.. .. ,..,....;...._. _,. ,_. . , W. ,. .,.;.... . . . . . .,.. ., . . a WM, . .0 ' ,' "' "is: 5,1.'::_"' "1;... tr... : .;,.~;:;_..; w: {Ha-xx; 5'1... . i""~""".1' .- 1,571.... 1L;;-;-a;s~, " , ,. a? 1;} " 1*. a 1" a. _ 4 ; ,;,;; 5% W? 4; ,:.._ ga tting, s; 1! :7 35 x; a ., as f 311 E35,. ', . ti "9 a; :.}!...2 r a W: 1* , a a! a ; , a! a, We. ,. -- a. ' .1 .1... ;_- 5:55.; 3.3; +5 kit-.9 .7 w :19]~ . i, 551 1 a}: 4;; - '17:.4; '+r$"-;,m- ...v.:f:;3$:a?gr( ,1 .1 ans .5 :;%;-;qu: f. ti-'t.;.-U;:-, '52:? , . 4.: > s; f. {a}; if 2_ In; ' . ' 7- 71$; gs --\ , ,.--. 3'13v'rkfk- f- ""531 91%; 3"??? X};- 9'.- w. it saw! as H ts : a s; a! a! rt-e 5 sea a: at '. a... an - a ;: as f. " i! *3! .13.}: ~ *1 . :!: s5 w 3.1;: :. .