[33] Thermal denaturation procedures for hemoglobin

Olsen, Kenneth W.

doi:10.1016/0076-6879(94)31035-1

Cited by 30 publications

(17 citation statements)

References 16 publications

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“…The degradation of artemisinin or Hb reported in previous studies (1,14,21,28,30,38) can most likely be explained by Hb denaturation and subsequent heme release mediated by organic solvents (21), reducing agents (7), or buffers or the use of a higher temperature (11,12,24,34). The stability of peroxide antimalarials with oxyHb is consistent with their antimalarial efficacy in vivo, the absence of toxicity toward healthy erythrocytes, and the notion that free heme or iron is required for peroxide activation and subsequent antimalarial activity.…”

Section: Figmentioning

confidence: 52%

“…Ex vivo, oxyHb is easily oxidized to form metHb, which readily undergoes denaturation to release heme and form insoluble hemichromes (10,18,34). Furthermore, the redox state and protein conformation of oxyHb are highly dependent on changes to solvents, buffers, and temperature (11,12,24,34). Conformational instability and release of heme from metHb (3,10,16,18) and oxyHb (12) solutions may significantly influence in vitro reactivity studies, and these studies may not accurately reflect the nature of intracellular oxyHb, which has a stabilized quaternary structure.…”

mentioning

confidence: 99%

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Stability of Peroxide Antimalarials in the Presence of Human Hemoglobin

Creek

Ryan

Charman

et al. 2009

Antimicrob Agents Chemother

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Peroxide antimalarials, including artemisinin, are important for the treatment of multidrug-resistant malaria. These peroxides are known to react with iron or heme to produce reactive intermediates that are thought to be responsible for their antimalarial activities. This study investigated the potential interaction of selected peroxide antimalarials with oxyhemoglobin, the most abundant form of iron in the human body. The observed stability of artemisinin derivatives and 1,2,4-trioxolanes in the presence of oxyhemoglobin was in contrast to previous reports in the literature. Spectroscopic analysis of hemoglobin found it to be unstable under the conditions used for previous studies, and it appears likely that the artemisinin reactivity reported in these studies may be attributed to free heme released by protein denaturation. The stability of peroxide antimalarials with intact oxyhemoglobin, and reactivity with free heme, may explain the selective toxicity of these antimalarials toward infected, but not healthy, erythrocytes.

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Section: Figmentioning

confidence: 52%

mentioning

confidence: 99%

Stability of Peroxide Antimalarials in the Presence of Human Hemoglobin

Creek

Ryan

Charman

et al. 2009

Antimicrob Agents Chemother

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“…A similar stable hemoglobin molecule was made by Bellelli and co-workers through double chemical crosslinking of human hemoglobin which maintained allosteric properties at 85°C (43). This is well above T m ϭ 53°C for the most stable carbonmonoxy form of uncrosslinked native hemoglobin A 0 (39,44).…”

Section: The Effect Of Molecular Size and Crosslinking Of Hemoglobin mentioning

confidence: 68%

“…The increase in the relative stability observed in the described experiments is consistent with the increase of T m , measured by differential scanning calorimetery (DSC) and/or other thermal denaturation experiments (A. Mathews and T. Fattor, personal communication) for hemoglobins expressed in di-␣ frame (pseudo-tetramers) vs expressed in mono-␣ frame (tetramers). For example, the T m of the carbonmonoxy form of rHb1.1 measured by DSC was 92°C vs 53°C for human hemoglobin A o (39).…”

Section: Figmentioning

confidence: 99%

Assessing the Relative Stabilities of Engineered Hemoglobins Using Electrospray Mass Spectrometry

Apostoł

1999

Analytical Biochemistry

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“…For example, ͉⌬f 0 met-Hb ͉ is smaller than ͉⌬f 0 HbCO ͉, even though the ͉⌬f sat ͉ values are about the same. These differences are most likely due to the lower stability against denaturation for met-Hb than for HbCO (34). Hence, the most likely explanation for the smaller ͉⌬f 0 ͉ for met-Hb than for HbCO close to the pIs, is a more pronounced surface-induced denaturation in the former case and, as a consequence an increased spreading on the surface.…”

Section: Discussionmentioning

confidence: 96%

Structural changes in hemoglobin during adsorption to solid surfaces: Effects of pH, ionic strength, and ligand binding

Höök

Rodahl

Kasemo

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

451

168

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We have studied the adsorption of two structurally similar forms of hemoglobin (met-Hb and HbCO) to a hydrophobic self-assembled methyl-terminated thiol monolayer on a gold surface, by using a Quartz Crystal Microbalance (QCM) technique. This technique allows time-resolved simultaneous measurements of changes in frequency ( f) (c.f. mass) and energy dissipation (D) (c.f. rigidity͞viscoelastic properties) of the QCM during the adsorption process, which makes it possible to investigate the viscoelastic properties of the different protein layers during the adsorption process. Below the isoelectric points of both met-Hb and HbCO, the ⌬D vs. ⌬f graphs displayed two phases with significantly different slopes, which indicates two states of the adsorbed proteins with different visco-elastic properties. The slope of the first phase was smaller than that of the second phase, which indicates that the first phase was associated with binding of a more rigidly attached, presumably denatured protein layer, whereas the second phase was associated with formation of a second layer of more loosely bound proteins. This second layer desorbed, e.g., upon reduction of Fe 3؉ of adsorbed met-Hb and subsequent binding of carbon monoxide (CO) forming HbCO. Thus, the results suggest that the adsorbed proteins in the second layer were in a native-like state. This information could only be obtained from simultaneous, time-resolved measurements of changes in both D and f, demonstrating that the QCM technique provides unique information about the mechanisms of protein adsorption to solid surfaces.

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[33] Thermal denaturation procedures for hemoglobin

Cited by 30 publications

References 16 publications

Stability of Peroxide Antimalarials in the Presence of Human Hemoglobin

Stability of Peroxide Antimalarials in the Presence of Human Hemoglobin

Assessing the Relative Stabilities of Engineered Hemoglobins Using Electrospray Mass Spectrometry

Structural changes in hemoglobin during adsorption to solid surfaces: Effects of pH, ionic strength, and ligand binding

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