Evaluation of human N-linked glycosylation sites in murine granulocyte-macrophage colony-stimulating factor

Scott W. Altmann, Michael B. Prystowsky

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

Nonglycosylated murine and human granulocyte-macrophage colony-stimulating factor have a molecular mass of ∼14.5 kDa predicted from the primary amino acid sequence. The expression of both proteins in COS cells leads to a heterogeneous population of molecules that differ in the degree of glycosylation. Both human and murine molecules contain two N-linked glycosylation sites that are situated in nonhomologous locations along the linear sequence. Despite this difference both proteins show a similar size distribution among the glycosylation variants. These studies analyze the effects of introducing in the murine protein novel N-linked glycosylation sites corresponding to those sites found in the human molecule. A panel of molecules composed of various combinations of human N-linked glycosylation sites in either the presence or the absence of murine N-linked glycosylation was compared. Substitution of a proper human N-linked glycosylation consensus sequence at Asn 24 did not result in N-linked glycosylation, nor was there any considerable effect on bioactivity. Replacement of the N-linked glycosylation consensus sequence at Asn 34 results in glycosylation similar to that found in the human molecule and causes a significant decrease in bioactivity. These data suggest that the position of N-linked glycosylation is critical for maximal bioactivity in a particular species and that the changes in position of these sites in different species probably occurred during evolution in response to changes in their receptors.

Original languageEnglish (US)
Pages (from-to)349-355
Number of pages7
JournalArchives of Biochemistry and Biophysics
Volume293
Issue number2
DOIs
Publication statusPublished - Mar 1992
Externally publishedYes

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ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology

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