Exploring Uniform, Dual, and Dynamic Topologies of Membrane Proteins by Substituted Cysteine Accessibility Method (SCAM™)

© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature..

A described simple and advanced protocol for Substituted Cysteine Accessibility Method as applied to transmembrane (TM) orientation (SCAM™) permits a topology analysis of proteins in their native state and can be universally adapted to any membrane system to either systematically map an uniform or identify and quantify the degree of mixed topology or establish transmembrane assembly dynamics from relatively static experimental data such as endpoint topologies of membrane proteins. In this approach, noncritical individual amino acids that are thought to reside in the putative extracellular or intracellular loops of a membrane protein are replaced one at the time by cysteine residue, and the orientation with respect to the membrane is evaluated by using a pair of membrane-impermeable non-detectable and detectable thiol-reactive labeling reagents. For the most water-exposed cysteine residues in proteins, the thiol pKa lies in the range of 8-9, and formation of cysteinyl thiolate ions is optimum in aqueous rather in a nonpolar environment. These features and the ease of specific chemical modification with thiol reagents are central to SCAM™. Membrane side-specific sulfhydryl labeling allows to discriminate "exposed, protected or dynamic" cysteines strategically "implanted" at desired positions throughout cysteine less target protein template. The strategy described is widely used to map the topology of membrane protein and establish its transmembrane dynamics in intact cells of both diderm (two-membraned) Gram-negative and monoderm (one-membraned) Gram-positive bacteria, cell-derived oriented membrane vesicles, and proteoliposomes.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:2715

Enthalten in:

Methods in molecular biology (Clifton, N.J.) - 2715(2024) vom: 06., Seite 121-157

Sprache:

Englisch

Beteiligte Personen:

Bogdanov, Mikhail [VerfasserIn]

Links:

Volltext

Themen:

Amino Acids
Cysteine
Journal Article
K848JZ4886
Maleimides
Membrane Proteins
Membrane protein
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
SCAM™
Sulfhydryl Compounds
Sulfhydryl Reagents
Topology

Anmerkungen:

Date Completed 07.11.2023

Date Revised 30.12.2023

published: Print

Citation Status MEDLINE

doi:

10.1007/978-1-0716-3445-5_9

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM364223588