Biglutaminyl-Biliverdin IX Alpha as a Heme Degradation Product in the Dengue Fever Insect-Vector Aedes aegypti
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- 作者：Luiza O. R. Pereira ; Pedro L. Oliveira ; Igor C. Almeida ; Gabriela O. Paiva-Silva
- 刊名：Biochemistry
- 出版年：2007
- 出版时间：June 12, 2007
- 年：2007
- 卷：46
- 期：23
- 页码：6822 - 6829
- 全文大小：215K
- 年卷期：v.46,no.23(June 12, 2007)
- ISSN：1520-4995
文摘
Hemoglobin digestion in the midgut of hematophagous animals results in the release of itsprosthetic group, heme, which is a pro-oxidant molecule. Heme enzymatic degradation is a protectivemechanism that has been described in several organisms, including plants, bacteria, and mammals. Thisreaction is catalyzed by heme oxygenase and results in formation of carbon monoxide, ferrous ion, andbiliverdin IX
. During digestion, a large amount of a green pigment is produced and secreted into theintestinal lumen of Aedes aegypti adult females. In the case of another blood-sucking insect, the kissing-bug Rhodnius prolixus, we have recently shown that heme degradation involves a complex pathway thatgenerates dicysteinyl-biliverdin IX gamma. The light absorption spectrum of the Aedes purified pigmentwas similar to that of biliverdin, but its mobility on a reverse-phase chromatography column suggesteda compound less hydrophobic than biliverdin IX. Structural characterization by ESI-MS revealed thatthe mosquito pigment is the isomer of biliverdin bound to two glutamine residues by an amide bond.This biglutaminyl-biliverdin is formed by oxidative cleavage of the heme porphyrin ring followed by twosubsequent additions of glutamine residues to the biliverdin IX. The role of this pathway in the adaptationof this insect vector to a blood-feeding habit is discussed.
. During digestion, a large amount of a green pigment is produced and secreted into theintestinal lumen of Aedes aegypti adult females. In the case of another blood-sucking insect, the kissing-bug Rhodnius prolixus, we have recently shown that heme degradation involves a complex pathway thatgenerates dicysteinyl-biliverdin IX gamma. The light absorption spectrum of the Aedes purified pigmentwas similar to that of biliverdin, but its mobility on a reverse-phase chromatography column suggesteda compound less hydrophobic than biliverdin IX. Structural characterization by ESI-MS revealed thatthe mosquito pigment is the isomer of biliverdin bound to two glutamine residues by an amide bond.This biglutaminyl-biliverdin is formed by oxidative cleavage of the heme porphyrin ring followed by twosubsequent additions of glutamine residues to the biliverdin IX. The role of this pathway in the adaptationof this insect vector to a blood-feeding habit is discussed.