Solution studies on heme proteins: Circular dichroism and optical rotation of Lumbricus terrestris and Glycera dibranchiata hemoglobin

Harrington, John P.; Pandolfelli, Emilia R.; Herskovits, Theodore T.

doi:10.1016/0005-2795(73)90330-9

Cited by 70 publications

(40 citation statements)

References 37 publications

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“…The HbCO was converted to HbO 2 with light and an atmosphere of O 2 at 0°C. metHb was prepared from HbO 2 by oxidation with an excess of K 3 Fe(CN) 6 . Spectral changes that accompany partial oxidation with K 3 Fe(CN) 6 are shown in Fig.…”

Section: Hemoglobin Of L Terrestris Molecular Weightmentioning

confidence: 99%

“…The ferrous CO-saturated abc trimer and met (ferric) chain d also associate to form (abcd) 4 The extracellular hemoglobins of annelids were first shown by Svedberg and Eriksson (1) to be gigantic molecules of at least 3 MDa in molecular mass. Although several subsequent studies gave molecular masses close to 4 MDa or higher for the Hb of Lumbricus terrestris and related species (2)(3)(4), recent studies by scanning transmission electron microscopy (5) have suggested masses of 3.5-3.6 MDa, and early light-scattering measurements suggested even lower values (6,7). A possible reason for this great variation in reported molecular masses is oxidation which has been shown to cause extensive dissociation of many annelid Hbs (8 -10).…”

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confidence: 99%

“…Oxidized Hb (or subunits) was made by adding various amounts of K 3 Fe(CN) 6 according to the experiment. Two sets of experiments were done: (i) 100% oxidized Hb was produced by adding K 3 Fe(CN) 6 (25-or 125-fold molar excess over the heme) in the dark 3 on ice overnight against N 2 -saturated 25 mM bis-tris propane, 100 mM NaCl, and 1 or 5 mM EGTA, pH 7.0. The K 3 Fe(CN) 6 was added in the same buffer.…”

mentioning

confidence: 99%

“…Two sets of experiments were done: (i) 100% oxidized Hb was produced by adding K 3 Fe(CN) 6 (25-or 125-fold molar excess over the heme) in the dark 3 on ice overnight against N 2 -saturated 25 mM bis-tris propane, 100 mM NaCl, and 1 or 5 mM EGTA, pH 7.0. The K 3 Fe(CN) 6 was added in the same buffer. Light-scattering experiments were performed on these solutions with the size-exclusion column equilibrated with the same buffer.…”

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confidence: 99%

“…The latter preparation without calcium is the same solution used for the dry weight determinations (16). Aliquots of each of these solutions were oxidized in the dark by adding K 3 Fe(CN) 6 as 5, 10, 25, 50, 75, 90, or 100% of the molar quantity of heme-iron. The actual percent oxidation was estimated from the change in absorbance.…”

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Assembly of the Gigantic Hemoglobin of the Earthworm Lumbricus terrestris

Zhu

Ownby

Riggs

et al. 1996

Journal of Biological Chemistry

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The extracellular hemoglobin of the earthworm Lumbricus terrestris has four major kinds of O 2 -binding chains: a, b, and c (forming a disulfide-linked trimer), and chain d. Non-heme, non-globin structural chains, "linkers," are also present. Light-scattering techniques have been used to show that the ferrous CO-saturated abc trimer and chain d form an (abcd) 4 complex of 285 kDa at neutral pH. Formation of the full-sized 4-MDa molecule requires the addition of linker chains in the proportion of two linkers per (abcd) 4 and occurs much more rapidly in the presence of 10 mM calcium. This stoichiometry is supported not only by direct quantitative analysis of the intact hemoglobin but also by the fact that the addition of 50% of the proposed stoichiometric quantity of linkers results in the conversion of 50% of the (abcd) 4 to full-sized molecules. Isolated COsaturated abc trimers self-associate to (abc) 2 and higher aggregates up to an apparent limit of (abc) 10 ϳ550 kDa. The extracellular hemoglobins of annelids were first shown by Svedberg and Eriksson (1) to be gigantic molecules of at least 3 MDa in molecular mass. Although several subsequent studies gave molecular masses close to 4 MDa or higher for the Hb of Lumbricus terrestris and related species (2-4), recent studies by scanning transmission electron microscopy (5) have suggested masses of 3.5-3.6 MDa, and early light-scattering measurements suggested even lower values (6, 7). A possible reason for this great variation in reported molecular masses is oxidation which has been shown to cause extensive dissociation of many annelid Hbs (8 -10). Goss et al. (9) used light scattering to show that oxidation of L. terrestris Hb at neutral pH caused a large drop in molecular weight. Similarly, Ascoli et al. (10) found that oxidation of the similar Hb from Octolasium complanatum 1 caused hemichrome formation and dissociation outside of a narrow range near pH 7.The stoichiometry has also been uncertain. The Hb of L. terrestris has four major kinds of O 2 -binding globin chains: a, b, and c (forming the disulfide-linked abc trimer) and chain d, together with non-heme structural chains, "linkers," designated L. Kapp et al. (11) and Vinogradov et al. (12) have reported that linkers comprise 33-36% of the total mass, but this conclusion was based largely on the staining of SDS-gels with Coomassie Blue. This dye, however, binds to different proteins to quite different extents (13,14). Ownby et al. (15) redetermined the stoichiometry by reverse-phase high performance liquid chromatography (HPLC).2 The weight proportions of linkers were found to be approximately 16.4% by two independent procedures: the integrated absorption of the HPLC peaks and amino acid analysis of these peaks. These results led to the conclusion that the overall stoichiometry is (abcd) 2 L. This stoichiometry is further supported by the results of SDS-capillary gel electrophoresis monitored at 214 nm (see our companion study (16)).The goals of the present experiments are to redetermine the molecu...

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Section: Hemoglobin Of L Terrestris Molecular Weightmentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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confidence: 99%

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confidence: 99%

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Assembly of the Gigantic Hemoglobin of the Earthworm Lumbricus terrestris

Zhu

Ownby

Riggs

et al. 1996

Journal of Biological Chemistry

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Cushioning the pressure vibration of a zeolite concentrator system using a decoupled balancing duct system

Chang¹,

Lin²

2007

Environ. Prog.

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A honeycomb Zeolite Rotor Concentrator (HZRC) is the main air pollution control device utilized by many semiconductor and optoelectronics manufacturers. Various plant exhaust streams are collected and then transferred to the HZRC for decontamination. In a conventional HZRC, the exhaust fan movement and the switching between different air ducts can cause significant duct pressure variations resulting in production interruption. The minimization of pressure fluctuations to ensure continuous operation of production lines while maintaining a high volatile organic compounds (VOCs) removal efficiency is essential for exhaust treatment in these high technology manufactures. The article introduces a decoupled balancing duct system (DBDS) for controlling the airflows to achieve a balanced pressure in the HZRC system by adding a flow rate control device to the VOCs loaded stream bypass duct of a conventional system. Performance comparisons of HZRC with DBDS and other air flow control systems used by the wafer manufacturers in Hsinchu Science Park, Taiwan are presented. DBDS system had been proved effectively to stabilize the pressure in the airflow ducts, and thus avoided pressure fluctuations; it helped to achieve a high VOCs removal efficiency while ensuring the stability of the HZRC.

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Crystal structures of unligated and CN‐ligated Glycera dibranchiata monomer ferric hemoglobin components III and IV

et al. 2002

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Erythrocytes of the marine annelid, Glycera dibranchiata, contain a mixture of monomeric and polymeric hemoglobins. There are three major monomer hemoglobin components, II, III, IV (also called GMH2, 3, and 4), that have been highly purified and well characterized. We have now crystallized GMH3 and GMH4 and determined their structures to 1.4-1.8 A resolution. The structures were determined for these two monomer hemoglobins in the oxidized (Fe3+, ferric, or met-) forms in both the unligated and cyanide-ligated states. This work differs from two published, refined structures of a Glycera dibranchiata monomer hemoglobin, which has a sequence that is substantially different from any bona fide major monomer hemoglobins (GMH2, 3, or 4). The high-resolution crystal structures (presented here) and the previous NMR structure of CO-ligated GMH4, provide a basis for interpreting structure/function details of the monomer hemoglobins. These details include: (1) the strong correlation between temperature factor and NMR dynamics for respective protein forms; (2) the unique nature of the HisE7Leu primary sequence substitutions in GMH3 and GMH4 and their impact on cyanide ion binding kinetics; (3) the LeuB10Phe difference between GMH3 and GMH4 and its impact on ligand binding; and (4) elucidation of changes in the structural details of the distal and proximal heme pockets upon cyanide binding.

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Solution studies on heme proteins: Circular dichroism and optical rotation of Lumbricus terrestris and Glycera dibranchiata hemoglobin

Cited by 70 publications

References 37 publications

Assembly of the Gigantic Hemoglobin of the Earthworm Lumbricus terrestris

Assembly of the Gigantic Hemoglobin of the Earthworm Lumbricus terrestris

Cushioning the pressure vibration of a zeolite concentrator system using a decoupled balancing duct system

Crystal structures of unligated and CN‐ligated Glycera dibranchiata monomer ferric hemoglobin components III and IV

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