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Location of a novel type of interpolypeptide chain linkage in the human protein HC-IgA complex (HC-IgA) and identification of a heterogeneous chromophore associated with the complex

Calero, M ; Escribano, J ; Grubb, Anders LU orcid and Méndez, E (1994) In The Journal of biological chemistry 269(1). p.384-389
Abstract

Protein HC (human complex-forming glycoprotein, heterogeneous in charge) is a member of the lipocalin superfamily of hydrophobic ligand-binding proteins. The quantitatively dominating blood plasma form of protein HC is a protein HC-IgA complex (HC-IgA), which is the fourth most abundant immunoglobulin species in plasma. A photodiode array detection system on-line with a high performance liquid chromatograph has allowed the identification of low amounts of a heterogeneous fluorescent chromophore covalently bound to HC-IgA, and displaying significant absorption in the visible region in resemblance to the free protein HC chromophore. Several structurally related chromophore-containing linked peptides, carrying 80% of the light absorption... (More)

Protein HC (human complex-forming glycoprotein, heterogeneous in charge) is a member of the lipocalin superfamily of hydrophobic ligand-binding proteins. The quantitatively dominating blood plasma form of protein HC is a protein HC-IgA complex (HC-IgA), which is the fourth most abundant immunoglobulin species in plasma. A photodiode array detection system on-line with a high performance liquid chromatograph has allowed the identification of low amounts of a heterogeneous fluorescent chromophore covalently bound to HC-IgA, and displaying significant absorption in the visible region in resemblance to the free protein HC chromophore. Several structurally related chromophore-containing linked peptides, carrying 80% of the light absorption at 330 nm of HC-IgA, were isolated from a pepsin-produced protein HC-alpha 1-nonapeptide. Sequence analysis of these linked peptides demonstrated that the bond between protein HC and IgA represents a novel type of reduction-resistant linkage between polypeptide chains and involves the cysteine residue 34 of protein HC and the penultimate cysteine residue of the carboxyl-terminal part of one of the IgA heavy chains, as well as the heterogeneous fluorescent chromophore. The light absorption and fluorescent spectra of the chromophore-linked peptides were similar to those of native free protein HC.

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author
; ; and
publishing date
type
Contribution to journal
publication status
published
keywords
Alpha-Globulins/chemistry, Amino Acid Sequence, Chromatography, High Pressure Liquid, Fluorescent Dyes, Humans, Immunoglobulin A/chemistry, Molecular Sequence Data, Oligopeptides/analysis, Pepsin A/metabolism, Protease Inhibitors/chemistry, Spectrum Analysis
in
The Journal of biological chemistry
volume
269
issue
1
pages
384 - 389
publisher
American Society for Biochemistry and Molecular Biology
external identifiers
  • scopus:0028057820
  • pmid:7506257
ISSN
0021-9258
language
English
LU publication?
no
id
7021b33a-a921-4dd0-88d3-a1d2c317c577
alternative location
https://www.sciencedirect.com/science/article/pii/S0021925817423611
date added to LUP
2021-10-28 13:37:26
date last changed
2024-01-12 02:57:14
@article{7021b33a-a921-4dd0-88d3-a1d2c317c577,
  abstract     = {{<p>Protein HC (human complex-forming glycoprotein, heterogeneous in charge) is a member of the lipocalin superfamily of hydrophobic ligand-binding proteins. The quantitatively dominating blood plasma form of protein HC is a protein HC-IgA complex (HC-IgA), which is the fourth most abundant immunoglobulin species in plasma. A photodiode array detection system on-line with a high performance liquid chromatograph has allowed the identification of low amounts of a heterogeneous fluorescent chromophore covalently bound to HC-IgA, and displaying significant absorption in the visible region in resemblance to the free protein HC chromophore. Several structurally related chromophore-containing linked peptides, carrying 80% of the light absorption at 330 nm of HC-IgA, were isolated from a pepsin-produced protein HC-alpha 1-nonapeptide. Sequence analysis of these linked peptides demonstrated that the bond between protein HC and IgA represents a novel type of reduction-resistant linkage between polypeptide chains and involves the cysteine residue 34 of protein HC and the penultimate cysteine residue of the carboxyl-terminal part of one of the IgA heavy chains, as well as the heterogeneous fluorescent chromophore. The light absorption and fluorescent spectra of the chromophore-linked peptides were similar to those of native free protein HC.</p>}},
  author       = {{Calero, M and Escribano, J and Grubb, Anders and Méndez, E}},
  issn         = {{0021-9258}},
  keywords     = {{Alpha-Globulins/chemistry; Amino Acid Sequence; Chromatography, High Pressure Liquid; Fluorescent Dyes; Humans; Immunoglobulin A/chemistry; Molecular Sequence Data; Oligopeptides/analysis; Pepsin A/metabolism; Protease Inhibitors/chemistry; Spectrum Analysis}},
  language     = {{eng}},
  number       = {{1}},
  pages        = {{384--389}},
  publisher    = {{American Society for Biochemistry and Molecular Biology}},
  series       = {{The Journal of biological chemistry}},
  title        = {{Location of a novel type of interpolypeptide chain linkage in the human protein HC-IgA complex (HC-IgA) and identification of a heterogeneous chromophore associated with the complex}},
  url          = {{https://www.sciencedirect.com/science/article/pii/S0021925817423611}},
  volume       = {{269}},
  year         = {{1994}},
}