Hemocyanin from the Australian freshwater crayfish Cherax destructor. Characterization of a dimeric subunit and its involvement in the formation of the 25S component

Jeffrey, Peter D.; Shaw, Douglas J.; Treacy, George

doi:10.1021/bi00608a021

Cited by 23 publications

(18 citation statements)

References 13 publications

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“…When monomers are dialysed back to neutral pH, in the presence of divalent ions, it is often found that hexamers are quantitatively reformed, but only partial (often 10-20 %) reconstitution of the expected dodecamer is achieved. This behaviour has been seen for example, with haemocyanin from Cancer magister (Carpenter & van Holde, 1973), Callinectes sapidus (Hamlin & Fish, 1977;Herskovits et al 1981a), Callianassa californiensis (Arisaka, I 977)» Cher ax destructor (Jeffrey, Shaw & Treacy, 1978) and Ligia exotica (Terwilliger et al 1979). It is easy to propose a reason for this behaviour.…”

Section: A)mentioning

confidence: 88%

Haemocyanins

Holde

Miller

1982

Quart. Rev. Biophys.

256

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About ten years ago, one of the authors participated in a review of haemocyanin structure and function (van Holde & van Bruggen, 1971). At that time, it was possible to describe the field in terms of a limited amount of exciting new structural information, and a long list of unanswered questions. While the stoichiometry of oxygen binding was understood, virtually nothing was known about the active site. Even the oxidation state of the copper was a matter of conjecture. The size of the haemocyanin polypeptide chains was the subject of intense debate, with very little substantive knowledge available. While the haemocyanins were known to be allosteric proteins, there were virtually no experimental studies of oxygen binding on a level that could be meaningfully interpreted in terms of extant theories.

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Section: A)mentioning

confidence: 88%

Haemocyanins

Holde

Miller

1982

Quart. Rev. Biophys.

256

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“…The monomers M I and M2 were separated in the same manner, but the polyacrylamide concentration was 5% and the buffer was 0.025 M glycine and 0.1 mM EGTA, pH 10.1. Further details may be found in a previous publication (Jeffrey et al, 1978). After separation, all fractions were dialyzed against 0.025 M Tris buffer, pH For the reassembly experiments, 1 mL of a solution of concentration 1 mg/mL of monomer M1 in the pH 7.8 Tris buffer was dialyzed for 48 h at room temperature vs. 2 250-mL volumes of the same buffer, 0.03 M with respect to calcium.…”

Section: Methodsmentioning

confidence: 99%

Hemocyanin from the Australian freshwater crayfish Cherax destructor. Electron microscopy of native and reassembled molecules

Jeffrey¹

1979

Biochemistry

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Examination and measurement of electron micrographs of negatively stained hemocyanin molecules from Cherax destructor show that the predominant aggregated forms, the 16S and 24S components, are typical structures for arthropod hexamers and dodecamers, respectively. In Cherax hemocyanin the hexamers are formed from the monomeric (Mr congruent to 75,000) subunits, M1 and M2, while the dodecamers contain in addition a dimeric (Mr congruent to 150,000) subunit, M3'. Studies of the composition of solutions of the subunits M1 and m2 to which calcium ions have been added at pH 7.8 show that, under these conditions, reassembly occurs to particles indistinguishable from native hexamers. It is noteworthy that dodecamers are not seen since this confirms the previous suggestion that incorporation of the dimeric subunit in the assembly process is necessary for their formation. The results obtained from Cherax hemocyanin are related to those of previous structural studies of arthropod hemocyanins. In particular, the possible controlling role of certain specific subunits in arthropod hemocyanin oligomers containing more than one kind of subunit is illustrated with a model for the Cherax dodecamer, in which the dimeric subunit is shared between the two halves of the molecule.

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“…Alkaline dissociation of the whole serum hemocyanin results in a number of electrophoretically distinguishable subunits (Figure 1). Of these subunits, three are in high amount and are identifiable with the Mj, M2, and M3' subunits described in previous papers (Murray & Jeffrey, 1974;Jeffrey et al, 1976Jeffrey et al, , 1978, now denoted as Mlb M2b and M3', respectively. The three new subunits reported here, Ml2, M22, and M4', are present in smaller amounts.…”

Section: Resultsmentioning

confidence: 70%

“…about 75 000 and a dimer of molecular weight ~150 000 (Murray & Jeffrey, 1974). Subsequently the role of these subunits in formation of the polymeric aggregates was studied (Jeffrey et al, 1976(Jeffrey et al, , 1978. More recently the existence of a fourth subunit has been demonstrated (Jeffrey et al, 1980), while in the present paper we report the identification of two more subunits.…”

mentioning

confidence: 59%

“…The involvement of certain specific subunits in the control of oligomer formation in arthropod hemocyanins is already clear in some instances. Thus, it is known in Limulus polyphemus hemocyanin that fraction V is required to form structures larger than 16 S (equivalent to 6 monomers) and fraction IV to form 60 S (equivalent to 48 monomers) from 34 S (equivalent to 24 monomers) (Bijlholt et al, 1979), in Androctonus hemocyanin that subunit 1-a heterodimer-is required to form 34 S (Lamy et al, 1977), in Eurypelma hemocyanin that subunit 4D-also a heterodimer-is required to form 34 S (Markl et al, 1979), and in Cherax hemocyanin that M3'-a homodimer-is required to form 25 S (equivalent 0006-2960/81 /0420-4816S01.25/0 © 1981 American Chemical Society to 12 monomers) (Jeffrey et al, 1978). In the case of Cherax the detection of more subunits implies that some amplification of the details of the previous discussion of the aggregation behavior is necessary.…”

mentioning

confidence: 99%

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Aggregation patterns in Cherax destructor hemocyanin: control of oligomer distribution by incorporation of specific subunits

Di¹,

Pd²,

Gb³

1981

Biochemistry

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Recent polyacrylamide gel electrophoresis studies on Cherax destructor hemocyanin have demonstrated the presence of three further constituent fractions in the alkaline dissociation product in addition to the three subunits reported in earlier work. Two of these recently discovered subunits are monomeric with molecular weights around 750000, while the third subunit is of similar size to the previously identified dimeric subunit M3' with a molecular weight near 150 000. The aggregation process is influenced by the presence of calcium ions, particularly in the distribution of hybrid hexameric species. However, the relative proportions, as well as the types of subunits present initially, are of primary importance in determining the oligomer distribution pattern obtained upon reconstitution from alkaline pH to pH 7.8 of selected mixtures of subunits. An additional significant factor in the assembly process has been proposed: the operation of different relative rates of aggregation between different types of subunits. Reconstitution experiments based on these findings substantially explain the complex distribution of oligomeric forms in C. destructor hemolymph.

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Hemocyanin from the Australian freshwater crayfish Cherax destructor. Characterization of a dimeric subunit and its involvement in the formation of the 25S component

Cited by 23 publications

References 13 publications

Haemocyanins

Haemocyanins

Hemocyanin from the Australian freshwater crayfish Cherax destructor. Electron microscopy of native and reassembled molecules

Aggregation patterns in Cherax destructor hemocyanin: control of oligomer distribution by incorporation of specific subunits

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