Heterogeneity of 125I-labeled epidermal growth factor

Lynn M. Matrisian; Stephen R. Planck; Joanne S. Finch; Bruce E. Magun

doi:10.1016/0304-4165(85)90030-3

Heterogeneity of ¹²⁵I-labeled epidermal growth factor

Lynn M. Matrisian, Stephen R. Planck, Joanne S. Finch, Bruce E. Magun

Research output: Contribution to journal › Article › peer-review

17 Scopus citations

Abstract

Highly purified epidermal growth factor (EGF) was iodinated, and the labeled product with the same isoelectric point as underivatized EGF was isolated by isoelectric focusing. When the ¹²⁵I-labeled EGF was analyzed by reverse-phase chromatography, the resulting profile of ¹²⁵I activity was much broader than the profile obtained with underivatized EGF. Rechromatography of ¹²⁵I-EGF fractions indicated that our highly-purified labelled EGF was indeed heterogenous. Analysis of each HPLC column fraction demonstrated that degradation of EGF had not occurred. The column fractions containing ¹²⁵I-EGF were pooled into five groups for analysis of cell binding characteristics. Scatchard plot analysis of the five ¹²⁵I-EGF pools revealed markedly different binding behaviors. In contrast, they had equal potency in stimulating DNA synthesis, within the sensitivity of our assay. Specific activity measurements indicated that the five HPLC pools of ¹²⁵I-EGF had varying numbers of ¹²⁵I atoms per EGF molecule. The heterogeneity of the highly purified ¹²⁵I-EGF and the binding characteristics of the ¹²⁵I-EGF subfractions pose serious implications for all workers who use iodinated ligands for receptor binding studies.

Original language	English (US)
Pages (from-to)	139-146
Number of pages	8
Journal	BBA - General Subjects
Volume	839
Issue number	2
DOIs	https://doi.org/10.1016/0304-4165(85)90030-3
State	Published - Apr 17 1985
Externally published	Yes

Keywords

Epidermal growth factor
Iodination
Receptor binding

ASJC Scopus subject areas

Biophysics
Biochemistry
Molecular Biology

Access to Document

10.1016/0304-4165(85)90030-3

Cite this

@article{9ae09de8415a43078b40a9a2cab438b1,

title = "Heterogeneity of 125I-labeled epidermal growth factor",

abstract = "Highly purified epidermal growth factor (EGF) was iodinated, and the labeled product with the same isoelectric point as underivatized EGF was isolated by isoelectric focusing. When the 125I-labeled EGF was analyzed by reverse-phase chromatography, the resulting profile of 125I activity was much broader than the profile obtained with underivatized EGF. Rechromatography of 125I-EGF fractions indicated that our highly-purified labelled EGF was indeed heterogenous. Analysis of each HPLC column fraction demonstrated that degradation of EGF had not occurred. The column fractions containing 125I-EGF were pooled into five groups for analysis of cell binding characteristics. Scatchard plot analysis of the five 125I-EGF pools revealed markedly different binding behaviors. In contrast, they had equal potency in stimulating DNA synthesis, within the sensitivity of our assay. Specific activity measurements indicated that the five HPLC pools of 125I-EGF had varying numbers of 125I atoms per EGF molecule. The heterogeneity of the highly purified 125I-EGF and the binding characteristics of the 125I-EGF subfractions pose serious implications for all workers who use iodinated ligands for receptor binding studies.",

keywords = "Epidermal growth factor, Iodination, Receptor binding",

author = "Matrisian, {Lynn M.} and Planck, {Stephen R.} and Finch, {Joanne S.} and Magun, {Bruce E.}",

note = "Funding Information: The technical assistance of Joel Finman and Herb Wagner, Jr. is gratefully acknowledged. This work was supported by NIH grants CA29290 and CA09213.",

year = "1985",

month = apr,

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doi = "10.1016/0304-4165(85)90030-3",

language = "English (US)",

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pages = "139--146",

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T1 - Heterogeneity of 125I-labeled epidermal growth factor

AU - Matrisian, Lynn M.

AU - Planck, Stephen R.

AU - Finch, Joanne S.

AU - Magun, Bruce E.

N1 - Funding Information: The technical assistance of Joel Finman and Herb Wagner, Jr. is gratefully acknowledged. This work was supported by NIH grants CA29290 and CA09213.

PY - 1985/4/17

Y1 - 1985/4/17

N2 - Highly purified epidermal growth factor (EGF) was iodinated, and the labeled product with the same isoelectric point as underivatized EGF was isolated by isoelectric focusing. When the 125I-labeled EGF was analyzed by reverse-phase chromatography, the resulting profile of 125I activity was much broader than the profile obtained with underivatized EGF. Rechromatography of 125I-EGF fractions indicated that our highly-purified labelled EGF was indeed heterogenous. Analysis of each HPLC column fraction demonstrated that degradation of EGF had not occurred. The column fractions containing 125I-EGF were pooled into five groups for analysis of cell binding characteristics. Scatchard plot analysis of the five 125I-EGF pools revealed markedly different binding behaviors. In contrast, they had equal potency in stimulating DNA synthesis, within the sensitivity of our assay. Specific activity measurements indicated that the five HPLC pools of 125I-EGF had varying numbers of 125I atoms per EGF molecule. The heterogeneity of the highly purified 125I-EGF and the binding characteristics of the 125I-EGF subfractions pose serious implications for all workers who use iodinated ligands for receptor binding studies.

AB - Highly purified epidermal growth factor (EGF) was iodinated, and the labeled product with the same isoelectric point as underivatized EGF was isolated by isoelectric focusing. When the 125I-labeled EGF was analyzed by reverse-phase chromatography, the resulting profile of 125I activity was much broader than the profile obtained with underivatized EGF. Rechromatography of 125I-EGF fractions indicated that our highly-purified labelled EGF was indeed heterogenous. Analysis of each HPLC column fraction demonstrated that degradation of EGF had not occurred. The column fractions containing 125I-EGF were pooled into five groups for analysis of cell binding characteristics. Scatchard plot analysis of the five 125I-EGF pools revealed markedly different binding behaviors. In contrast, they had equal potency in stimulating DNA synthesis, within the sensitivity of our assay. Specific activity measurements indicated that the five HPLC pools of 125I-EGF had varying numbers of 125I atoms per EGF molecule. The heterogeneity of the highly purified 125I-EGF and the binding characteristics of the 125I-EGF subfractions pose serious implications for all workers who use iodinated ligands for receptor binding studies.

KW - Epidermal growth factor

KW - Iodination

KW - Receptor binding

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