Self-association and oxygen-binding characteristics of the isolated subunits of Limulus polyphemus hemocyanin

Michael D. Brenowitz, Celia Bonaventura, Joseph Bonaventura

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

The hemocyanin of the horseshoe crab Limulus polyphemus is characteristic of arthropod hemocyanins in that it is a high-molecular-weight oligomer composed of functionally and structurally distinct subunits. The protein forms a 48-subunit complex, the largest form of arthropod hemocyanin, whose oxygen-binding characteristics are modulated by subunit interaction within the oligomer. It has previously been shown that a number of electrophoretic isozymes, which are identical immunochemically, are present in dissociated Limulus hemocyanin. In this study it is demonstrated that the electrophoretic differences in the antigenically identical subunits are not reflected in their oxygen-binding and self-assembly properties or in the roles they play in reassembly and function of the 48-subunit native molecule. The chloride-dependent modulation of the oxygen-binding properties of those Limulus subunits which do not self-assemble, as documented here, illustrates that this allosteric effect may be operable at the tertiary level. For each of the purified subunits the effects of pH and calcium ions on oxygen-binding characteristics and self-assembly reactions are reported, and the roles of specific subunits in reassembly of distinct aggregation states are further documented.

Original languageEnglish (US)
Pages (from-to)238-249
Number of pages12
JournalArchives of Biochemistry and Biophysics
Volume230
Issue number1
DOIs
StatePublished - 1984
Externally publishedYes

Fingerprint

Horseshoe Crabs
Hemocyanin
Oxygen
Arthropods
Oligomers
Self assembly
Isoenzymes
Chlorides
Agglomeration
Molecular Weight
Molecular weight
Modulation
Ions
Calcium
Molecules
Proteins

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

Cite this

Self-association and oxygen-binding characteristics of the isolated subunits of Limulus polyphemus hemocyanin. / Brenowitz, Michael D.; Bonaventura, Celia; Bonaventura, Joseph.

In: Archives of Biochemistry and Biophysics, Vol. 230, No. 1, 1984, p. 238-249.

Research output: Contribution to journalArticle

@article{b29b4fa90fbb40d69e38ff891bd8c1d9,
title = "Self-association and oxygen-binding characteristics of the isolated subunits of Limulus polyphemus hemocyanin",
abstract = "The hemocyanin of the horseshoe crab Limulus polyphemus is characteristic of arthropod hemocyanins in that it is a high-molecular-weight oligomer composed of functionally and structurally distinct subunits. The protein forms a 48-subunit complex, the largest form of arthropod hemocyanin, whose oxygen-binding characteristics are modulated by subunit interaction within the oligomer. It has previously been shown that a number of electrophoretic isozymes, which are identical immunochemically, are present in dissociated Limulus hemocyanin. In this study it is demonstrated that the electrophoretic differences in the antigenically identical subunits are not reflected in their oxygen-binding and self-assembly properties or in the roles they play in reassembly and function of the 48-subunit native molecule. The chloride-dependent modulation of the oxygen-binding properties of those Limulus subunits which do not self-assemble, as documented here, illustrates that this allosteric effect may be operable at the tertiary level. For each of the purified subunits the effects of pH and calcium ions on oxygen-binding characteristics and self-assembly reactions are reported, and the roles of specific subunits in reassembly of distinct aggregation states are further documented.",
author = "Brenowitz, {Michael D.} and Celia Bonaventura and Joseph Bonaventura",
year = "1984",
doi = "10.1016/0003-9861(84)90105-X",
language = "English (US)",
volume = "230",
pages = "238--249",
journal = "Archives of Biochemistry and Biophysics",
issn = "0003-9861",
publisher = "Academic Press Inc.",
number = "1",

}

TY - JOUR

T1 - Self-association and oxygen-binding characteristics of the isolated subunits of Limulus polyphemus hemocyanin

AU - Brenowitz, Michael D.

AU - Bonaventura, Celia

AU - Bonaventura, Joseph

PY - 1984

Y1 - 1984

N2 - The hemocyanin of the horseshoe crab Limulus polyphemus is characteristic of arthropod hemocyanins in that it is a high-molecular-weight oligomer composed of functionally and structurally distinct subunits. The protein forms a 48-subunit complex, the largest form of arthropod hemocyanin, whose oxygen-binding characteristics are modulated by subunit interaction within the oligomer. It has previously been shown that a number of electrophoretic isozymes, which are identical immunochemically, are present in dissociated Limulus hemocyanin. In this study it is demonstrated that the electrophoretic differences in the antigenically identical subunits are not reflected in their oxygen-binding and self-assembly properties or in the roles they play in reassembly and function of the 48-subunit native molecule. The chloride-dependent modulation of the oxygen-binding properties of those Limulus subunits which do not self-assemble, as documented here, illustrates that this allosteric effect may be operable at the tertiary level. For each of the purified subunits the effects of pH and calcium ions on oxygen-binding characteristics and self-assembly reactions are reported, and the roles of specific subunits in reassembly of distinct aggregation states are further documented.

AB - The hemocyanin of the horseshoe crab Limulus polyphemus is characteristic of arthropod hemocyanins in that it is a high-molecular-weight oligomer composed of functionally and structurally distinct subunits. The protein forms a 48-subunit complex, the largest form of arthropod hemocyanin, whose oxygen-binding characteristics are modulated by subunit interaction within the oligomer. It has previously been shown that a number of electrophoretic isozymes, which are identical immunochemically, are present in dissociated Limulus hemocyanin. In this study it is demonstrated that the electrophoretic differences in the antigenically identical subunits are not reflected in their oxygen-binding and self-assembly properties or in the roles they play in reassembly and function of the 48-subunit native molecule. The chloride-dependent modulation of the oxygen-binding properties of those Limulus subunits which do not self-assemble, as documented here, illustrates that this allosteric effect may be operable at the tertiary level. For each of the purified subunits the effects of pH and calcium ions on oxygen-binding characteristics and self-assembly reactions are reported, and the roles of specific subunits in reassembly of distinct aggregation states are further documented.

UR - http://www.scopus.com/inward/record.url?scp=0021414376&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0021414376&partnerID=8YFLogxK

U2 - 10.1016/0003-9861(84)90105-X

DO - 10.1016/0003-9861(84)90105-X

M3 - Article

VL - 230

SP - 238

EP - 249

JO - Archives of Biochemistry and Biophysics

JF - Archives of Biochemistry and Biophysics

SN - 0003-9861

IS - 1

ER -