Reference

Stereoselective synthesis of stable isotope labeled L-a-amino acids: synthesis of L-[4-13C] and L-[3,4-113C2]aspartic acid

Stereoselective synthesis of stable isotope labeled L-a-amino acids: synthesis of L-[4-13C] and L-[3,4-113C2]aspartic acid. Lodwig, Siegfried N.; Unkefer, Clifford J. (Natl. Stable Isot. Resour., Los Alamos Natl. Lab., Los Alamos, NM 87545, USA). J. Labelled Compd. Radiopharm., 31(2), 95-102 (English) 1992. CODEN: JLCRD4. ISSN: 0362-4803. 1145-80-8 and 26054-60-4 are also in the experiment. DOCUMENT TYPE: Journal CA Section: 34 (Amino Acids, Peptides, and Proteins) A stereoselective route to isotopically labeled L-aspartic acid using L-serine as a chiral precursor was developed. Labeled serine, prepd. biosynthetically, was N-protected by conversion to the N-tert-butoxycarbonyl (Boc) deriv. Boc-[3-13C]serine is cyclized to its b-lactone which was treated with K13CN to yield L-b-[3,4-13C2]cyanoalanine. Hydrolysis of the cyanoalanine yielded L-[3,4-13C2]aspartic acid. Similarly, L-[4-13C]aspartate was produced from L-serine and K13CN. Using this route, the L-enantiomer was produced in 96% excess. .

Transition state analogs for protein farnesyltransferase

Transition state analogs for protein farnesyltransferase. Cassidy, Pamela B.; Poulter, C.In this study， 26054-60-4 and 14000-31-8 are also used. Dale (Department of Chemistry, University of Utah, Salt Lake City, UT 84112, USA). Journal of the American Chemical Society, 118(36), 8761-8762 (English) 1996 American Chemical Society. CODEN: JACSAT. ISSN: 0002-7863. DOCUMENT TYPE: Journal CA Section: 7 (Enzymes) Protein farnesyltransferase (I) catalyzes the alkylation of a Cys residue near the C-terminus in several eukaryotic proteins. This is an essential post-translation modification of Ras proteins (pRas) involved in signal transduction that targets them to the inner surface of the plasma membrane where they serve as important on/off switches in the signal transduction network for cell division. The observation that farnesylation is necessary for oncogenic forms of pRas to transform cells has resulted in a considerable effort to find inhibitors of the enzyme. Here, the authors synthesized L-b-farnesylaminoalanine (faA) and the tetrapeptide, faAVIA, as a new class of inhibitors featuring an ammonium moiety designed to mimic a transition state proposed for the nucleophilic alkylation of Cys by farnesyl diphosphate (FPP). The ammonium analogs inhibited yeast I with IC50 values of 51 mM for faA and 14 mM for faAVIA. Although inorg. pyrophosphate was a weak inhibitor (Ki = 2.4 mM) of I, it interacted synergistically with faAVIA to lower the IC50 for the tetrapeptide 35-fold. The behavior of these analogs supported the hypothesis that the alkylation of Cys by FPP is an electrophilic reaction. .