MTSL

MTSL
Names
Preferred IUPAC name
{2,2,5,5-Tetramethyl-3-[(2-methyl-2,2-dioxo-2λ6-disulfan-1-yl)methyl]-2,5-dihydro-1H-pyrrol-1-yl}oxyl
Other names
MTSL
Identifiers
3D model (JSmol)
ChemSpider
  • InChI=1S/C10H18NO3S2/c1-9(2)6-8(7-15-16(5,13)14)10(3,4)11(9)12/h6H,7H2,1-5H3 checkY
    Key: BLSCGBLQCTWVPO-UHFFFAOYSA-N checkY
  • InChI=1/C10H18NO3S2/c1-9(2)6-8(7-15-16(5,13)14)10(3,4)11(9)12/h6H,7H2,1-5H3
    Key: BLSCGBLQCTWVPO-UHFFFAOYAW
  • CC1(C=C(C(N1[O])(C)C)CSS(=O)(=O)C)C
Properties
C10H18NO3S2
Molar mass 264.38 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

MTSL (S-(1-oxyl-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrol-3-yl)methyl methanesulfonothioate) is an organosulfur compound that is used as a nitroxide spin label.[1] MTSL is bifunctional, consisting of the nitroxide and the thiosulfonate ester functional groups. The nitroxide label is sterically protected, so it is relatively unreactive.

Labeling

MTSL is attached to proteins by reaction with thiol groups. The reaction exploits standard reactivity of thiosulfate esters. Methanesulfinate (CH3SO2−) is the leaving group:

RSO2S-nitroxide + protein-SH → protein-S-S-nitroxide + RSO2H

The heterodisulfide bond to the cysteine residue is robust, enabling site-directed spin labelling.[2][3] The MTSL moiety will add 184.3 daltons to the mass of the protein or peptide to which it is attached. The cysteine can be introduced using site-directed mutagenesis, and hence most positions in a protein can be labelled.

Spectroscopy

In Nuclear magnetic resonance the introduction of the paramagnetic group increases the relaxation rate of nearby nuclei.[1] Its presence can be detected as peak broadening and loss of intensity in peaks corresponding to nearby nuclei. Hence proximity can be inferred for all nuclei, that are affected. A major advantage of this method over traditional methods for obtaining distance restraints in protein NMR is the increased length, as paramagnetic relaxation enhancement can detect distances up to 25 Å (2.5 nm) as opposed to about 6 Å (0.6 nm) using the nuclear Overhauser effect. Spin labelling with MTSL is frequently used in investigation of residual structure in intrinsically unstructured proteins.

References

  1. ^ a b Christian Altenbach, Kyoung-Joon Oh, René J. Trabanino, Kálmán Hideg, Wayne L. Hubbell "Estimation of Inter-Residue Distances in Spin Labeled Proteins at Physiological Temperatures:  Experimental Strategies and Practical Limitations" Biochemistry, 2001, volume 40, pp 15471–15482. doi:10.1021/bi011544w
  2. ^ Kenyon, G.L. and Bruice, T.W. (1977). Novel sulfhydryl reagents. Methods In Enzymology 47, 407-430. doi:10.1016/0076-6879(77)47042-3
  3. ^ Berliner, L.J., Grunwald, J., Hankovszky, H.O., Hideg, K. (1982). A novel reversible thiol-specific spin label: papain active site labeling and inhibition. Analytical Biochemistry 119, 450-455. doi:10.1016/0003-2697(82)90612-1

Content Disclaimer

Informasi ini disarikan dari Wikipedia dan disajikan kembali untuk tujuan edukasi. Konten tersedia di bawah lisensi CC BY-SA 3.0. Kami tidak bertanggung jawab atas ketidakakuratan data yang bersumber dari kontribusi publik tersebut.

  1. The information displayed on this website is sourced in part or in whole from Wikipedia and has been adapted for the purpose of restating it. We strive to provide accurate and relevant information, however:
  2. There is no guarantee of absolute accuracy. Wikipedia is an open, collaborative project that can be edited by anyone, so information is subject to change.
  3. It is not intended to constitute professional advice. The content displayed is for informational and educational purposes only. For important decisions (e.g., medical, legal, or financial), please consult a professional.
  4. Content copyright. Wikipedia is licensed under the Creative Commons Attribution-ShareAlike License (CC BY-SA). This means that content may be reused with appropriate attribution and shared under a similar license.
  5. Responsible use. Any risk arising from the use of information from this website is entirely the responsibility of the user.