Tags

Type your tag names separated by a space and hit enter

Chemical and thermal unfolding of glypican-1: protective effect of heparan sulfate against heat-induced irreversible aggregation.
Biochemistry. 2009 Oct 27; 48(42):9994-10004.B

Abstract

Glypicans are cell-surface heparan sulfate proteoglycans that influence Wnt, hedgehog, decapentaplegic, and fibroblast growth factor activity via their heparan sulfate chains. However, recent studies have shown that glypican core proteins also have a role in growth factor signaling. Here, we expressed secreted recombinant human glypican-1 in eukaryotic cells. Recombinant glypican-1 was expressed as two glycoforms, one as proteoglycan substituted with heparan sulfate chains and one as the core protein devoid of glycosaminoglycans. Far-UV circular dichroism (CD) analysis of glypican-1 isolated under native conditions showed that the glypican-1 core protein is predominantly alpha-helical in structure, with identical spectra for the core protein and the proteoglycan form. The conformational stability of glypican-1 core protein to urea and guanidine hydrochloride denaturation was monitored by CD and fluorescence spectroscopy and showed a single unfolding transition at high concentrations of the denaturant (5.8 and 2.6 M, respectively). Renaturation from guanidine hydrochloride gave far-UV CD and fluorescence spectra identical to the spectra of native glypican-1. Thermal denaturation monitored by CD and differential scanning calorimetry (DSC) showed a single structural transition at a temperature of approximately 70 degrees C. Refolding of the heat-denatured glypican-1 core protein was dependent on protein concentration, suggesting that intermolecular interactions are involved in irreversible denaturation. However, refolding was concentration-independent for the proteoglycan form, suggesting that O-glycosylation protects the protein from irreversible aggregation. In summary, we have shown that the glypican-1 core protein is a stable alpha-helical protein and that the proteoglycan form of glypican-1 is protected from heat-induced aggregation.

Authors+Show Affiliations

Department of Experimental Medical Science, Division of Neuroscience, Glycobiology Group, Lund University, Biomedical Center A13, SE-221 84 Lund, Sweden. gabriel.svensson@med.lu.seNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

19775117

Citation

Svensson, Gabriel, et al. "Chemical and Thermal Unfolding of Glypican-1: Protective Effect of Heparan Sulfate Against Heat-induced Irreversible Aggregation." Biochemistry, vol. 48, no. 42, 2009, pp. 9994-10004.
Svensson G, Linse S, Mani K. Chemical and thermal unfolding of glypican-1: protective effect of heparan sulfate against heat-induced irreversible aggregation. Biochemistry. 2009;48(42):9994-10004.
Svensson, G., Linse, S., & Mani, K. (2009). Chemical and thermal unfolding of glypican-1: protective effect of heparan sulfate against heat-induced irreversible aggregation. Biochemistry, 48(42), 9994-10004. https://doi.org/10.1021/bi901402x
Svensson G, Linse S, Mani K. Chemical and Thermal Unfolding of Glypican-1: Protective Effect of Heparan Sulfate Against Heat-induced Irreversible Aggregation. Biochemistry. 2009 Oct 27;48(42):9994-10004. PubMed PMID: 19775117.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Chemical and thermal unfolding of glypican-1: protective effect of heparan sulfate against heat-induced irreversible aggregation. AU - Svensson,Gabriel, AU - Linse,Sara, AU - Mani,Katrin, PY - 2009/9/25/entrez PY - 2009/9/25/pubmed PY - 2009/12/16/medline SP - 9994 EP - 10004 JF - Biochemistry JO - Biochemistry VL - 48 IS - 42 N2 - Glypicans are cell-surface heparan sulfate proteoglycans that influence Wnt, hedgehog, decapentaplegic, and fibroblast growth factor activity via their heparan sulfate chains. However, recent studies have shown that glypican core proteins also have a role in growth factor signaling. Here, we expressed secreted recombinant human glypican-1 in eukaryotic cells. Recombinant glypican-1 was expressed as two glycoforms, one as proteoglycan substituted with heparan sulfate chains and one as the core protein devoid of glycosaminoglycans. Far-UV circular dichroism (CD) analysis of glypican-1 isolated under native conditions showed that the glypican-1 core protein is predominantly alpha-helical in structure, with identical spectra for the core protein and the proteoglycan form. The conformational stability of glypican-1 core protein to urea and guanidine hydrochloride denaturation was monitored by CD and fluorescence spectroscopy and showed a single unfolding transition at high concentrations of the denaturant (5.8 and 2.6 M, respectively). Renaturation from guanidine hydrochloride gave far-UV CD and fluorescence spectra identical to the spectra of native glypican-1. Thermal denaturation monitored by CD and differential scanning calorimetry (DSC) showed a single structural transition at a temperature of approximately 70 degrees C. Refolding of the heat-denatured glypican-1 core protein was dependent on protein concentration, suggesting that intermolecular interactions are involved in irreversible denaturation. However, refolding was concentration-independent for the proteoglycan form, suggesting that O-glycosylation protects the protein from irreversible aggregation. In summary, we have shown that the glypican-1 core protein is a stable alpha-helical protein and that the proteoglycan form of glypican-1 is protected from heat-induced aggregation. SN - 1520-4995 UR - https://www.unboundmedicine.com/medline/citation/19775117/Chemical_and_thermal_unfolding_of_glypican_1:_protective_effect_of_heparan_sulfate_against_heat_induced_irreversible_aggregation_ L2 - https://doi.org/10.1021/bi901402x DB - PRIME DP - Unbound Medicine ER -