Validation of l‐Tellurienylalanine as a Phenylalanine Isostere

Abstract

Mass cytometry (MC) and imagingm ass cytometry (IMC TM ) have emergeda si mportant tools for the study of biological heterogeneity.W er ecently demonstrated the use of l-2-tellurienylalanine (TePhe),amimic of phenylalanine (Phe), as an MCand IMC-compatible protein synthesis reporter.I nt his work, the biochemical similarity of TePhe and its cognate analogue, Phe, are examined in the contexto ft he RNase Sc omplex. Isothermalt itration calorimetry studies show that incorporation of TePhe preserves the interaction of S-peptide with S-protein, and the dissociation constants for the interaction of the Phe and Te Phep eptides are within af actor of two. The resulting RNase Sc omplex is catalytically active without significant alterations in the enzyme'skinetic parameters. Furthermore, circular dichroism spectroscopy does not reveal any changes to the secondary structure of Te Phe-substituted RNase S. These findings provide strong evidence that Te Phe functions as aPhe isostere in the context of afolded protein. It is anticipated that incorporation of Te Phe into peptides or peptidomimetic scaffolds will enablefacile generation of MC and IMC TM probes.[a] Dr.

The results of the comparative amino acid analysis of species of hedysarum growing in the North Caucasus

“…Полноценный синтез белков невозможен при нехватке незаменимых аминокислот, вследствие чего нарушается работа целого ряда систем и возникают различные заболевания. Изучение аминокислотного состава при проведении комплексного фармакогностического анализа является одним из обязательных направлений исследований, так как аминокислоты участвуют в биогенезе многих биологически активных соединений, в том числе ксантонов [8,10,12,13,[15][16][17][18]. Известно, что основными компонентами биосинтеза ксантонов являются ацетил-КоА, мева-лоновая и шикимовая кислоты, из которых синтезируется в дальнейшем фенилаланин.…”

Incorporation of TePhe into Expressed Proteins is Minimally Perturbing

“…We recently reported the effects of complete replacement of a single Phe residue by TePhe in the S-peptide of RNAse S via a semisynthetic approach. [20] TePhe was found to be stable in the context of the S-peptide and preserved the biophysical and enzymatic properties of RNAse S.…”

“…[14][15][16] The bio-incorporation of telluromethionine (TeMet, the heteroatomic analogue of L-methionine) was reported in 1994, [15] but the goal of broadly using tellurium to provide of phase information in diffraction experiments has yet to be realized, largely due to the instability of TeMet to aerobic oxidation, resulting in the modification/degradation of proteins carrying TeMet at surface-exposed sites. [14][15][16][17][18][19] We envision that L-tellurienylalanine (TePhe), a tellurium-bearing analogue of the canonical amino acid L-phenylalanine (Phe), [10,20] may circumvent these issues should it prove to be an appropriate isostere (Figure 1). The tellurophene side chain of TePhe is similar in size, shape and polarity to that of Phe and, owing to its aromaticity, is much less sensitive to oxidative degradation than the telluroether of TeMet.…”

“…While TePhe was invented as a global protein synthesis probe for mass cytometry and imaging mass cytometry, which require low levels of bio‐incorporation (<1% of Phe sites replaced by TePhe) for satisfactory signal, [10] we have since turned our attention toward the use of TePhe in fields such as structural biology which require higher levels of incorporation. We recently reported the effects of complete replacement of a single Phe residue by TePhe in the S‐peptide of RNAse S via a semisynthetic approach [20] . TePhe was found to be stable in the context of the S‐peptide and preserved the biophysical and enzymatic properties of RNAse S.…”

Semisynthesis of Human Ribonuclease–S

“… − A truncated variant of S-peptide (residues 1–15) also forms an active complex . By preparation of synthetic variants of S-peptide, a wide array of chemical modifications have been incorporated into RNase S. The ensuing data have enhanced our understanding of protein structure, protein folding, protein–protein interactions, and enzymology. − , S-peptide can even serve as an affinity tag for the purification and detection of recombinant proteins. − In recent studies, semisynthetic RNase S variants have been used to stabilize α-helices via peptide stapling, , control peptide–protein binding with photoswitchable peptides, and validate l -tellurienylalanine as a phenylalanine isostere …”