Radiation inactivation of human γ-interferon: Cellular activation requires two dimers

Jerome A. Langer, Abbas Rashidbaigi, Gianni Garotta, Ellis Kempner

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

γ-Interferon (IFN-γ) is a 17-kDa broad-spectrum cytokine which exerts its effects on a variety of target cells through its interaction with the IFN-γ receptor. Although physicochemical studies of Escherichia coli- derived IFN-γ, as well as its crystal structure, demonstrate that it is a homodimer in solution (M(r) 34,000), previous radiation inactivation studies yielded a functional size for IFN-γ of 63-73 kDa in an antiviral assay. To understand the relationship between the solution form of IFN-γ and the moiety that actually binds to the cellular receptor and activates cells, we examined irradiated nonradioactive and 32P-labeled IFN-γ for its migration in SDS/polyacrylamide gels (to determine its physical integrity), its binding to cells, its reactivity in an ELISA, and its antiviral activity. The functional size of IFN-γ differed in the assays, being 22 ± 2 kDa for the physical destruction of IFN-γ, 56 ± 2 kDa for the cellular binding assay, 45-50 kDa for reactivity in the ELISA, and 72 ± 6 kDa for antiviral activity. The results from the binding assays constitute direct evidence that IFN-γ binds to its cellular receptor as a dimer. However, for antiviral activity, the functional mass is equivalent to a tetramer. This is consistent with models involving ligand-induced receptor dimerization, whereby two dimers acting in concert (equivalent to the target size of a tetramer) are required to activate cells in the antiviral assay.

Original languageEnglish (US)
Pages (from-to)5818-5822
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume91
Issue number13
DOIs
StatePublished - Jun 21 1994

Fingerprint

Interferons
Antiviral Agents
Radiation
Enzyme-Linked Immunosorbent Assay
Dimerization
Cytokines
Escherichia coli
Ligands

All Science Journal Classification (ASJC) codes

  • General

Keywords

  • receptor
  • target size

Cite this

@article{62c74d3c8318486ab0464bb92fc42a2c,
title = "Radiation inactivation of human γ-interferon: Cellular activation requires two dimers",
abstract = "γ-Interferon (IFN-γ) is a 17-kDa broad-spectrum cytokine which exerts its effects on a variety of target cells through its interaction with the IFN-γ receptor. Although physicochemical studies of Escherichia coli- derived IFN-γ, as well as its crystal structure, demonstrate that it is a homodimer in solution (M(r) 34,000), previous radiation inactivation studies yielded a functional size for IFN-γ of 63-73 kDa in an antiviral assay. To understand the relationship between the solution form of IFN-γ and the moiety that actually binds to the cellular receptor and activates cells, we examined irradiated nonradioactive and 32P-labeled IFN-γ for its migration in SDS/polyacrylamide gels (to determine its physical integrity), its binding to cells, its reactivity in an ELISA, and its antiviral activity. The functional size of IFN-γ differed in the assays, being 22 ± 2 kDa for the physical destruction of IFN-γ, 56 ± 2 kDa for the cellular binding assay, 45-50 kDa for reactivity in the ELISA, and 72 ± 6 kDa for antiviral activity. The results from the binding assays constitute direct evidence that IFN-γ binds to its cellular receptor as a dimer. However, for antiviral activity, the functional mass is equivalent to a tetramer. This is consistent with models involving ligand-induced receptor dimerization, whereby two dimers acting in concert (equivalent to the target size of a tetramer) are required to activate cells in the antiviral assay.",
keywords = "receptor, target size",
author = "Langer, {Jerome A.} and Abbas Rashidbaigi and Gianni Garotta and Ellis Kempner",
year = "1994",
month = "6",
day = "21",
doi = "10.1073/pnas.91.13.5818",
language = "English (US)",
volume = "91",
pages = "5818--5822",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
number = "13",

}

Radiation inactivation of human γ-interferon : Cellular activation requires two dimers. / Langer, Jerome A.; Rashidbaigi, Abbas; Garotta, Gianni; Kempner, Ellis.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 91, No. 13, 21.06.1994, p. 5818-5822.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Radiation inactivation of human γ-interferon

T2 - Cellular activation requires two dimers

AU - Langer, Jerome A.

AU - Rashidbaigi, Abbas

AU - Garotta, Gianni

AU - Kempner, Ellis

PY - 1994/6/21

Y1 - 1994/6/21

N2 - γ-Interferon (IFN-γ) is a 17-kDa broad-spectrum cytokine which exerts its effects on a variety of target cells through its interaction with the IFN-γ receptor. Although physicochemical studies of Escherichia coli- derived IFN-γ, as well as its crystal structure, demonstrate that it is a homodimer in solution (M(r) 34,000), previous radiation inactivation studies yielded a functional size for IFN-γ of 63-73 kDa in an antiviral assay. To understand the relationship between the solution form of IFN-γ and the moiety that actually binds to the cellular receptor and activates cells, we examined irradiated nonradioactive and 32P-labeled IFN-γ for its migration in SDS/polyacrylamide gels (to determine its physical integrity), its binding to cells, its reactivity in an ELISA, and its antiviral activity. The functional size of IFN-γ differed in the assays, being 22 ± 2 kDa for the physical destruction of IFN-γ, 56 ± 2 kDa for the cellular binding assay, 45-50 kDa for reactivity in the ELISA, and 72 ± 6 kDa for antiviral activity. The results from the binding assays constitute direct evidence that IFN-γ binds to its cellular receptor as a dimer. However, for antiviral activity, the functional mass is equivalent to a tetramer. This is consistent with models involving ligand-induced receptor dimerization, whereby two dimers acting in concert (equivalent to the target size of a tetramer) are required to activate cells in the antiviral assay.

AB - γ-Interferon (IFN-γ) is a 17-kDa broad-spectrum cytokine which exerts its effects on a variety of target cells through its interaction with the IFN-γ receptor. Although physicochemical studies of Escherichia coli- derived IFN-γ, as well as its crystal structure, demonstrate that it is a homodimer in solution (M(r) 34,000), previous radiation inactivation studies yielded a functional size for IFN-γ of 63-73 kDa in an antiviral assay. To understand the relationship between the solution form of IFN-γ and the moiety that actually binds to the cellular receptor and activates cells, we examined irradiated nonradioactive and 32P-labeled IFN-γ for its migration in SDS/polyacrylamide gels (to determine its physical integrity), its binding to cells, its reactivity in an ELISA, and its antiviral activity. The functional size of IFN-γ differed in the assays, being 22 ± 2 kDa for the physical destruction of IFN-γ, 56 ± 2 kDa for the cellular binding assay, 45-50 kDa for reactivity in the ELISA, and 72 ± 6 kDa for antiviral activity. The results from the binding assays constitute direct evidence that IFN-γ binds to its cellular receptor as a dimer. However, for antiviral activity, the functional mass is equivalent to a tetramer. This is consistent with models involving ligand-induced receptor dimerization, whereby two dimers acting in concert (equivalent to the target size of a tetramer) are required to activate cells in the antiviral assay.

KW - receptor

KW - target size

UR - http://www.scopus.com/inward/record.url?scp=0028342833&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028342833&partnerID=8YFLogxK

U2 - 10.1073/pnas.91.13.5818

DO - 10.1073/pnas.91.13.5818

M3 - Article

C2 - 8016072

AN - SCOPUS:0028342833

VL - 91

SP - 5818

EP - 5822

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

SN - 0027-8424

IS - 13

ER -