Liganded and unliganded forms of Antarctic fish haemoglobins in polyethylene glycol: crystallization of an R-state haemichrome intermediate.
Liganded and unliganded forms of two Antarctic fish haemoglobins, from Trematomus newnesi and T. bernacchii, have been crystallized in low-salt media using polyethylene glycol as precipitant. In particular, crystals of air-exposed T. newnesi carbomonoxy haemoglobin were found to be isomorphous to the crystals grown in high-salt media. Preliminary X-ray analysis of the diffraction data revealed that the beta-haem iron of this haemoglobin is in the haemichrome state, with both the proximal and distal histidyl residues linked to the iron. This is the first crystallization of a haemichrome intermediate of a vertebrate haemoglobin.
Riccio
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Istituto di Biochimica delle Proteine ed Enzimologia, CNR, Via Marconi 12, I-80125 Naples, Italy.
Vitagliano
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di Prisco
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Zagari
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Mazzarella
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D000818:Animals; D000864:Antarctic Regions; D003460:Crystallization; D018360:Crystallography, X-Ray; D006420:Hemeproteins / Q000737:chemistry*; D006454:Hemoglobins / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D010473:Perciformes; D011092:Polyethylene Glycols / Q000737:chemistry; D011487:Protein Conformation
D006420:Hemeproteins; D006454:Hemoglobins; D008024:Ligands; C001332:hemichrome; D011092:Polyethylene Glycols