Fluorescence Studies of Extracellular Hemoglobin of Glossoscolex paulistus in Met Form Obtained from Sephadex Gel Filtration

Ferric species equilibrium of the giant extracellular hemoglobin of Glossoscolex paulistus in alkaline medium: HALS hemichrome as a precursor of pentacoordinate species

“…Previous reports, which used only optical spectroscopies, suggested the existence of a high-spin hemichrome species, but this is not the case [22,23]. Our data show that HALS hemichrome, which is the bis-histidine complex that has the highest g, presents also S = 1/2.…”

“…The absorbance of the samples at 415 nm was kept below 1.0 using a 1 cm path length cell, with concentration of approximately 0.2 mg mL −1 [22].…”

Autofluorescence characterization of advanced glycation end products of hemoglobin

“…The studies on the effect of various pH shows that the fluorescence intensity was maximum at the pH 9.0 with the corresponding highest QY of 0.211. This supports the earlier finding of increased QY of intrinsic fluorescence of hemoglobin due to tryptophan in the alkaline condition [16]. Between the two buffers tested, no significant variation was observed in the fluorescence intensity values.…”

Ferric species of the giant extracellular hemoglobin of Glossoscolex paulistus as function of pH: An EPR study on the irreversibility of the heme transitions

“…It is important to notice that previous works have demonstrated the occurrence of a process, at least partially irreversible, of oligomeric dissociation after pH changes (Moreira et al, 2008a;Santiago et al, 2008Santiago et al, , 2007Ribelatto et al, 2006Ribelatto et al, , 2005Agustinho et al, 1996Agustinho et al, , 1997. Likewise, it has been demonstrated that in alkaline (Moreira et al, 2008b) as well as in acid medium , the heme ferric transitions caused by more drastic pH transitions propitiate a process of secondary structure loss, which is detected by Circular Dichroism (CD), that is intrinsically related to the modifications that occur in the first sphere coordination of the ferric center.…”