A three-step kinetic mechanism for peptide binding to MHC class II proteins

Ravi V. Joshi, Jennifer A. Zarutskie, Lawrence J. Stern

Research output: Contribution to journalArticle

52 Citations (Scopus)

Abstract

Peptide binding reactions of class II MHC proteins exhibit unusual kinetics, with extremely slow apparent rate constants for the overall association (< 100 M-1 s-1) and dissociation (< 10-5 s-1) processes. Various linear and branched pathways have been proposed to account for these data. Using fluorescence resonance energy transfer between tryptophan residues in the MHC peptide binding site and aminocoumarin-labeled peptides, we measured real-time kinetics of peptide binding to empty class II MHC proteins. Our experiments identified an obligate intermediate in the binding reaction. The observed kinetics were consistent with a binding mechanism that involves an initial bimolecular binding step followed by a slow unimolecular conformational change. The same mechanism is observed for different peptide antigens. In addition, we noted a reversible inactivation of the empty MHC protein that competes with productive binding. The implications of this kinetic mechanism for intracellular antigen presentation pathways are discussed.

Original languageEnglish (US)
Pages (from-to)3751-3762
Number of pages12
JournalBiochemistry
Volume39
Issue number13
DOIs
StatePublished - Apr 4 2000

Fingerprint

Peptides
Kinetics
Aminocoumarins
Proteins
Antigens
Fluorescence Resonance Energy Transfer
Tryptophan
Antigen Presentation
Rate constants
Binding Sites
Association reactions
MHC binding peptide
Experiments

ASJC Scopus subject areas

  • Biochemistry

Cite this

A three-step kinetic mechanism for peptide binding to MHC class II proteins. / Joshi, Ravi V.; Zarutskie, Jennifer A.; Stern, Lawrence J.

In: Biochemistry, Vol. 39, No. 13, 04.04.2000, p. 3751-3762.

Research output: Contribution to journalArticle

Joshi, Ravi V. ; Zarutskie, Jennifer A. ; Stern, Lawrence J. / A three-step kinetic mechanism for peptide binding to MHC class II proteins. In: Biochemistry. 2000 ; Vol. 39, No. 13. pp. 3751-3762.
@article{00dc4259ea0847a38573c89f7b4abc1a,
title = "A three-step kinetic mechanism for peptide binding to MHC class II proteins",
abstract = "Peptide binding reactions of class II MHC proteins exhibit unusual kinetics, with extremely slow apparent rate constants for the overall association (< 100 M-1 s-1) and dissociation (< 10-5 s-1) processes. Various linear and branched pathways have been proposed to account for these data. Using fluorescence resonance energy transfer between tryptophan residues in the MHC peptide binding site and aminocoumarin-labeled peptides, we measured real-time kinetics of peptide binding to empty class II MHC proteins. Our experiments identified an obligate intermediate in the binding reaction. The observed kinetics were consistent with a binding mechanism that involves an initial bimolecular binding step followed by a slow unimolecular conformational change. The same mechanism is observed for different peptide antigens. In addition, we noted a reversible inactivation of the empty MHC protein that competes with productive binding. The implications of this kinetic mechanism for intracellular antigen presentation pathways are discussed.",
author = "Joshi, {Ravi V.} and Zarutskie, {Jennifer A.} and Stern, {Lawrence J.}",
year = "2000",
month = "4",
day = "4",
doi = "10.1021/bi9923656",
language = "English (US)",
volume = "39",
pages = "3751--3762",
journal = "Biochemistry",
issn = "0006-2960",
publisher = "American Chemical Society",
number = "13",

}

TY - JOUR

T1 - A three-step kinetic mechanism for peptide binding to MHC class II proteins

AU - Joshi, Ravi V.

AU - Zarutskie, Jennifer A.

AU - Stern, Lawrence J.

PY - 2000/4/4

Y1 - 2000/4/4

N2 - Peptide binding reactions of class II MHC proteins exhibit unusual kinetics, with extremely slow apparent rate constants for the overall association (< 100 M-1 s-1) and dissociation (< 10-5 s-1) processes. Various linear and branched pathways have been proposed to account for these data. Using fluorescence resonance energy transfer between tryptophan residues in the MHC peptide binding site and aminocoumarin-labeled peptides, we measured real-time kinetics of peptide binding to empty class II MHC proteins. Our experiments identified an obligate intermediate in the binding reaction. The observed kinetics were consistent with a binding mechanism that involves an initial bimolecular binding step followed by a slow unimolecular conformational change. The same mechanism is observed for different peptide antigens. In addition, we noted a reversible inactivation of the empty MHC protein that competes with productive binding. The implications of this kinetic mechanism for intracellular antigen presentation pathways are discussed.

AB - Peptide binding reactions of class II MHC proteins exhibit unusual kinetics, with extremely slow apparent rate constants for the overall association (< 100 M-1 s-1) and dissociation (< 10-5 s-1) processes. Various linear and branched pathways have been proposed to account for these data. Using fluorescence resonance energy transfer between tryptophan residues in the MHC peptide binding site and aminocoumarin-labeled peptides, we measured real-time kinetics of peptide binding to empty class II MHC proteins. Our experiments identified an obligate intermediate in the binding reaction. The observed kinetics were consistent with a binding mechanism that involves an initial bimolecular binding step followed by a slow unimolecular conformational change. The same mechanism is observed for different peptide antigens. In addition, we noted a reversible inactivation of the empty MHC protein that competes with productive binding. The implications of this kinetic mechanism for intracellular antigen presentation pathways are discussed.

UR - http://www.scopus.com/inward/record.url?scp=0034603779&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034603779&partnerID=8YFLogxK

U2 - 10.1021/bi9923656

DO - 10.1021/bi9923656

M3 - Article

C2 - 10736175

AN - SCOPUS:0034603779

VL - 39

SP - 3751

EP - 3762

JO - Biochemistry

JF - Biochemistry

SN - 0006-2960

IS - 13

ER -