Characterization of rat lutropin charge microheterogeneity using chromatofocusing

Brooks Allen Keel, H. Edward Grotjan

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Chromatofocusing was utilized to separate rat lutropin isohormones. The pH gradients generated were highly reproducible, allowing accurate comparisons of isohormones in different elution profiles. Extracts of anterior pituitaries from intact male rats yielded at least seven species of immunoreactive lutropin after chromatofocusing. Five species exhibited apparent pI's in the range 8.97 to 9.25. Two additional peaks of rat lutropin were also observed: one in the void volume (pI > 9.8) and one which bound to the column but could be eluted with 1.0 m NaCl (pI < 7.0). All seven lutropin isohormones were active in an in vitro bioassay. The biological-to-immunological (B:I) assay ratios were directly related to the apparent pI. The presence of both the basic and the acidic species of biologically active rat lutropin has not been previously observed with isoelectric focusing. Chromatofocusing should prove to be a valuable analytical tool in the isolation and characterization of gonadotropin isohormones.

Original languageEnglish (US)
Pages (from-to)267-270
Number of pages4
JournalAnalytical Biochemistry
Volume142
Issue number2
DOIs
StatePublished - Nov 1 1984
Externally publishedYes

Fingerprint

Luteinizing Hormone
Rats
Proton-Motive Force
Bioassay
Isoelectric Focusing
Gonadotropins
Biological Assay
Assays

Keywords

  • glycoproteins
  • hormone assays
  • isoelectric focusing
  • pH determination
  • protein chromatography
  • protein hormones

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

Cite this

Characterization of rat lutropin charge microheterogeneity using chromatofocusing. / Keel, Brooks Allen; Grotjan, H. Edward.

In: Analytical Biochemistry, Vol. 142, No. 2, 01.11.1984, p. 267-270.

Research output: Contribution to journalArticle

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