1384
G. S. M. Sundaram et al.
flash photolysis and ab initio molecular orbital theory. J Am
Chem Soc 120(18):4430–4438
Gothelf K, Jørgensen K (1998) Asymmetric 1, 3-dipolar cycloaddi-
tion reactions. Chem Rev 98(2):863–910
Hatanaka Y, Sadakane Y (2002) Photoaffinity labeling in drug
discovery and developments: chemical gateway for entering
proteomic frontier. Curr Top Med Chem 2(3):271–288
Hermonson GT (1996) Bioconjugate techniques. Elsevier, San Diego
Heymer B, Haferkamp O, Schmid WC (1970) Preparation and use
of fluorescein isothiocyanate-labelled streptococcal cell-wall
preparations (Pellois and Muir 2006) of proteins, or in
solid-phase synthesis. The current list of genetically
encoded amino acids is largely dominated by commercially
available amino acids. To continue to enhance the utility of
these powerful methods to translationally modifying pro-
teins, the development of amino acids with diverse struc-
tures and unique reactivity is clearly warranted. To this
end, we have detailed the synthesis of three novel amino
acids. We are currently investigating the feasibility of these
molecules as candidates to further expand the genetic code.
carbohydrates.
140(5):457–467
Z Immunitatsforsch Allerg Klin Immunol
Hino N, Okazaki Y, Kobayashi T, Hayashi A, Sakamoto K,
Yokoyama S (2005) Protein photo-cross-linking in mammalian
cells by site-specific incorporation of a photoreactive amino acid.
Nat Methods 2(3):201–206
Materials and methods
Hubbell WL, Cafiso DS, Altenbach C (2000) Identifying conforma-
tional changes with site-directed spin labeling. Nat Struct Biol
7(9):735–739
Lee HS, Spraggon G, Schultz PG, Wang F (2009) Genetic incorpo-
ration of a metal-ion chelating amino acid into proteins as a
biophysical probe. J Am Chem Soc 131(7):2481–2483
Liu D, Schultz P (1999) Progress toward the evolution of an organism
with an expanded genetic code. Proc Natl Acad Sci USA
96(9):4780–4785
Neumann H, Hazen JL, Weinstein J, Mehl RA, Chin JW (2008)
Genetically encoding protein oxidative damage. J Am Chem Soc
130(12):4028–4033
Pellois JP, Muir TW (2006) Semisynthetic proteins in mechanistic
studies: using chemistry to go where nature can’t. Curr Opin
Chem Biol 10(5):487–491
NMR spectra were recorded at 400 MHz (1H NMR) and
100 MHz (13C NMR) in CDCl3 solution at 25°C, if not
otherwise indicated, with the solvent signals as internal
reference. Reactions which required an inert atmosphere
were carried out under dry N2 with flame-dried glassware.
All commercial reagents were purchased from Sigma-
Aldrich Company Ltd. (Poole, United Kingdom). High
resolution mass spectra were recorded on a ESI-Orbitrap
instrument.
Acknowledgments This research was supported by the Engineering
and Physical Sciences Research Council in UK. We would like to
thank Dr R. Jenkins for his expert advice and help with the analytical
analysis.
Platz MS (2002) Comparison of phenylcarbene and phenylnitrene.
Acc Chem Res 28(12):487–492
Platz M, Admasu AS, Kwiatkowski S, Crocker PJ, Imai N, Watt DS
(1991) Photolysis of 3-aryl-3-(trifluoromethyl)diazirines: a caveat
regarding their use in photoaffinity probes. Bioconjug Chem
2(5):337–341
Scott W, O’Donnell M, Delgado F, Alsina J (2002) A solid-phase
synthetic route to unnatural amino acids with diverse side-chain
substitutions. J Org Chem 67(9):2960–2969
Slonczewski JL, Rosen BP, Alger JR, Macnab RM (1981) pH
homeostasis in Escherichia coli: measurement by 31P nuclear
magnetic resonance of methylphosphonate and phosphate. Proc
Natl Acad Sci USA 78(10):6271–6275
References
Atkinson RN, Moore L, Tobin J, King SB (1999) Asymmetric
synthesis of conformationally restricted L-arginine analogues as
active site probes of nitric oxide synthase. J Org Chem
64(10):3467–3475
Bond MR, Zhang H, Vu PD, Kohler JJ (2009) Photocrosslinking of
glycoconjugates using metabolically incorporated diazirine-con-
taining sugars. Nat Protoc 4(7):1044–1063
Brunner J (1996) Use of photocrosslinkers in cell biology. Trends
Cell Biol 6(4):154–157
Stryer L (1995) Biochemistry, 4th edn. Freeman and Company,
New York
Suchanek M, Radzikowska A, Thiele C (2005) Photo-leucine and
photo-methionine allow identification of protein-protein interac-
tions in living cells. Nat Methods 2(4):261–267
Buchmueller KL, Hill BT, Platz MS, Weeks KM (2003) RNA-
tethered phenyl azide photocrosslinking via a short-lived indis-
criminant electrophile. J Am Chem Soc 125(36):10850–10861
Degani Y, Heller A (1988) Direct electrical communication between
chemically modified enzymes and metal electrodes. 2. Methods
for bonding electron-transfer relays to glucose oxidase and
D-amino-acid oxidase. J Am Chem Soc 110:2615
Delpierre GR, Fruton JS (1966) Specific Inactivation of pepsin by a
diazo ketone. Proc Natl Acad Sci USA 56(6):1817–1822
Floyd RA, Kopke RD, Choi CH, Foster SB, Doblas S, Towner RA
(2008) Nitrones as therapeutics. Free Radic Biol Med
45(10):1361–1374
Tidwell T (2006) Ketene chemistry after 100 years: ready for a new
century. Eur J Org Chem 2006(3):563–576
Vermes I, Haanen C, Steffens-Nakken H, Reutelingsperger C (1995)
A novel assay for apoptosis. Flow cytometric detection of
phosphatidylserine expression on early apoptotic cells using fluo-
rescein labelled Annexin V. J Immunol Methods 184(1):39–51
Xie J, Schultz PG (2006) A chemical toolkit for proteins—an
expanded genetic code. Nat Rev Mol Cell Biol 7:775–782
Zhao M, Kalai T, Hideg K, Altenbach C, Hubbell WL, Kaback HR
(2000) Binding of spin-labeled galactosides to the lactose
permease of Escherichia coli. Biochemistry 39(37):11381–
11388
Ford F, Yuzawa T, Platz MS, Matzinger S, Fulscher M (1998)
Rearrangement of dimethylcarbene to propene: study by laser
123