Structural and functional properties of hemoglobins from unicellular organisms as revealed by resonance Raman spectroscopy

Egawa, Tsuyoshi; Yeh, Syun Ru

doi:10.1016/j.jinorgbio.2004.10.017

Cited by 95 publications

(167 citation statements)

References 154 publications

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“…The Fe-His stretching frequency of Ctb (226 cm -1 shown in Fig. 5) is similar to results obtained for other trHbs, lying between 220 and 232 cm -1 (13,25,34,35,37). In mammalian Hb or Mb, the imidazole ring of the proximal histidine is in an eclipsed orientation with respect to the pyrrole nitrogen atoms of the porphyrin, in contrast to a staggered orientation in the trHbs (36).…”

Section: Group III Trhbssupporting

confidence: 83%

“…5 and Fig. 6) show Ctb to have an atypical ν Fe-CO stretching mode at 514 cm -1 , compared to the other truncated hemoglobins that have been characterized so far (13,26,31). The TyrB10, HisE7 and the TrpG8 in Ctb are highly conserved in the group III trHbs, suggesting ligand stabilisation roles of these residues in Ctb.…”

Section: Group III Trhbsmentioning

confidence: 80%

“…This H-bonding interaction is not present in any of the trHbs with known structures, consistent with their relatively lower ν Fe-His . Taken together, these observations suggest that the proximal histidine ligand of Ctb has neutral character and has its imidazole ring in a staggered position with respect to the pyrrole nitrogen atoms of the porphyrin ring (13,25,31,(34)(35)(36)(37)(38).…”

Section: Group III Trhbsmentioning

confidence: 97%

“…Raman measurements with Soret excitation were taken with previously described instrumentation (13,25,26). Briefly, the 413.2 nm line of a krypton ion laser (Spectra Physics, Mountain View, CA) was used as an excitation source.…”

Section: Resonance Raman Techniquesmentioning

confidence: 99%

“…The E11 residue is conserved in group III trHbs as leucine or isoleucine. In trHbs of group II, for instance trHbN from Mycobacterium tuberculosis and the trHb from Chlamydomonas eugametos, this position is occupied by a polar residue, which is involved in the formation of a hydrogen bonding network with heme-bound ligands (11,13,14).…”

Section: Sequence Analysesmentioning

confidence: 99%

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Purification and Spectroscopic Characterization of Ctb, a Group III Truncated Hemoglobin Implicated in Oxygen Metabolism in the Food-Borne Pathogen Campylobacter jejuni

et al. 2006

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Campylobacter jejuni is a foodborne bacterial pathogen that possesses two distinct hemoglobins, encoded by the ctb and cgb genes. The former codes for a truncated hemoglobin (Ctb) in group III, an assemblage of uncharacterized globins in diverse clinically-and technologically-significant bacteria. Here, we show that Ctb purifies as a monomeric, predominantly oxygenated species. Optical spectra of ferric, ferrous, O 2 -and CO-bound forms resemble those of other hemoglobins. However, resonance Raman analysis shows Ctb to have an atypical ν Fe-CO stretching mode at 514 cm -1 , compared to the other truncated hemoglobins that have been characterized so far. This implies unique roles in ligand stabilisation for TyrB10, HisE7 and TrpG8, residues highly conserved within group III truncated hemoglobins. Since C. jejuni is a microaerophile, and a ctb mutant exhibits O 2 -dependent growth defects, one of the hypothesised roles of Ctb is in the detoxification, sequestration or transfer of O 2 The midpoint potential (E h ) of Ctb was found to be −33 mV, but no evidence was obtained in vitro to support the hypothesis that Ctb is reducible by NADH or NADPH. This truncated hemoglobin may function in the facilitation of O 2 transfer to one of the terminal oxidases of C. jejuni or instead facilitate O 2 transfer to Cgb for NO detoxification.In the past three decades, our understanding of hemoglobins has grown to recognise new classes of proteins in addition to the classical vertebrate α-and β-globins, myoglobin and the symbiotic Hbs of leguminous plants. These 'new' globins -some of which may actually be amongst the oldest, or ancestral, globins in a phylogenetic context (1) -include the non-symbiotic plant Hbs, chimeric flavohemoglobins, and the trHbs. Globins may be classified functionally -into those that detoxify NO and those that are involved in O 2 transfer or detoxification -or structurally into three categories (2). The first structural category contains flavoHbs that possess a C-terminal ferredoxin-NADP + reductase-like domain and an N-terminal globin domain; bacterial (3,4) and yeast (5) examples function in the enzymic removal of NO to produce nitrate (6,7). The second category contains single domain Hbs that are very similar to the N-terminal domain of the flavoHbs; however, their functions appear more varied than those of the flavoHbs. As an example, Vgb, found in the obligate aerobe Vitreoscilla, is believed to function in the facilitation of O 2 transfer to cytochrome bo' (8), whereas the C.

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Section: Group III Trhbssupporting

confidence: 83%

Section: Group III Trhbsmentioning

confidence: 80%

Section: Group III Trhbsmentioning

confidence: 97%

Section: Resonance Raman Techniquesmentioning

confidence: 99%

Section: Sequence Analysesmentioning

confidence: 99%

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Purification and Spectroscopic Characterization of Ctb, a Group III Truncated Hemoglobin Implicated in Oxygen Metabolism in the Food-Borne Pathogen Campylobacter jejuni

et al. 2006

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Structural determinants of ligand binding in truncated hemoglobins: Resonance Raman spectroscopy of the native states and their carbon monoxide and hydroxide complexes

et al. 2018

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The ligand binding characteristics of heme-containing proteins are determined by a number of factors, including the nature and conformation of the distal residues and their capability to stabilize the heme-bound ligand via hydrogen-bonding and electrostatic interactions. In this regard, the heme pockets of truncated hemoglobins (TrHbs) constitute an interesting case study as they share many common features, including a number of polar cavity residues. In this review, we will focus on three proteins of group II TrHbs, from Thermobifida fusca (Tf-HbO) and Pseudoalteromonas haloplanktis TAC125 (Ph-HbO). Although the residues in positions G8 (Trp) and B10 (Tyr) are conserved in all three proteins, the CD1 residue is a Tyr in T. fusca and a His in P. haloplanktis. Comparison of the ligand binding characteristics of these proteins, in particular the hydroxo and CO ligands by means of resonance Raman spectroscopy, reveals that this single difference in the key heme cavity residues markedly affects their ligand binding capability and conformation. Furthermore, although the two Ph-HbOs (Ph-HbO-2217 and Ph-HbO-0030) have identical key cavity residues, they display distinct ligand binding properties.

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A PEGylated bovine hemoglobin as a potent hemoglobin‐based oxygen carrier

Wang

et al. 2016

Biotechnology Progress

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Hemoglobin (Hb)-based oxygen carriers (HBOCs) have been used as blood substitutes in surgery medicine and oxygen therapeutics for ischemic stroke. As a potent HBOC, the PEGylated Hb has received much attention for its oxygen delivery and plasma expanding ability. Two PEGylated Hbs, Euro-Hb, and MP4 have been developed for clinical trials, using human adult hemoglobin (HbA) as the original substrate. However, HbA was obtained from outdated human blood and its quantity available from this source may not be sufficient for mass production of PEGylated HbA. In contrast, bovine Hb (bHb) has no quantity constraints for its ample resource. Thus, bHb is of potential to function as an alternative substrate to obtain a PEGylated bHb (bHb-PEG). bHb-PEG was prepared under the same reaction condition as HbA-PEG, using maleimide chemistry. The structural, functional, solution and physiological properties of bHb-PEG were determined and compared with those of HbA-PEG. bHb-PEG showed higher hydrodynamic volume, colloidal osmotic pressure, viscosity and P than HbA-PEG. The high P of bHb can partially compensate the PEGylation-induced perturbation in the R to T state transition of HbA. bHb-PEG was non-vasoactive and could efficiently recover the mean arterial pressure of mice suffering from hemorrhagic shock. Thus, bHb-PEG is expected to function as a potent HBOC for its high oxygen delivery and strong plasma expanding ability. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:252-260, 2017.

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Structural and functional properties of hemoglobins from unicellular organisms as revealed by resonance Raman spectroscopy

Cited by 95 publications

References 154 publications

Purification and Spectroscopic Characterization of Ctb, a Group III Truncated Hemoglobin Implicated in Oxygen Metabolism in the Food-Borne Pathogen Campylobacter jejuni

Purification and Spectroscopic Characterization of Ctb, a Group III Truncated Hemoglobin Implicated in Oxygen Metabolism in the Food-Borne Pathogen Campylobacter jejuni

Structural determinants of ligand binding in truncated hemoglobins: Resonance Raman spectroscopy of the native states and their carbon monoxide and hydroxide complexes

A PEGylated bovine hemoglobin as a potent hemoglobin‐based oxygen carrier

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