Hemoglobins Likely Function as Peroxidase in Blood ClamTegillarca granosaHemocytes.
Hemoglobins are a group of respiratory proteins principally functioning in transport of oxygen and carbon dioxide in red blood cells of all vertebrates and some invertebrates. The blood clamT. granosais one of the few invertebrates that have hemoglobin-containing red hemocytes. In the present research, the peroxidase activity ofT. granosahemoglobins (Tg-Hbs) was characterized and the associated mechanism of action was deciphered via structural comparison with other known peroxidases. We detected that purified Tg-Hbs catalyzed the oxidation of phenolic compounds in the presence of exogenous H2O2. Tg-Hbs peroxidase activity reached the maximum at pH 5 and 35°C and was inhibited by Fe2+, Cu2+, SDS, urea, and sodium azide. Tg-Hbs shared few similarities in amino acid sequence and overall structural characteristics with known peroxidases. However, the predicted structure at their heme pocket was highly similar to that of horseradish peroxidase (HRP) and myeloperoxidase (MPO). This research represented the first systemic characterization of hemoglobin as a peroxidase.
School of Marine Sciences, Ningbo University, Ningbo 315211, China; Zhejiang Key Laboratory of Aquatic Germplasm Resources, Zhejiang Wanli University, Ningbo 315100, China.
Sufang
0000-0002-0275-0265
S
Wang
Zhejiang Key Laboratory of Aquatic Germplasm Resources, Zhejiang Wanli University, Ningbo 315100, China.
Xiaopei
X
Yu
Zhejiang Key Laboratory of Aquatic Germplasm Resources, Zhejiang Wanli University, Ningbo 315100, China.
Zhihua
Z
Lin
Zhejiang Key Laboratory of Aquatic Germplasm Resources, Zhejiang Wanli University, Ningbo 315100, China.
Shunqin
0000-0003-1082-6407
S
Zhang
School of Marine Sciences, Ningbo University, Ningbo 315211, China.
Liangyi
L
Xue
Zhejiang Key Laboratory of Aquatic Germplasm Resources, Zhejiang Wanli University, Ningbo 315100, China.
Qinggang
0000-0002-8434-7620
Q
Xue
Zhejiang Key Laboratory of Aquatic Germplasm Resources, Zhejiang Wanli University, Ningbo 315100, China.
Yongbo
0000-0002-8268-1887
Y
Bao
D000595:Amino Acid Sequence; D000818:Animals; D049893:Arcidae / Q000378:metabolism*; D006434:Hemocytes / Q000378:metabolism*; D006454:Hemoglobins / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000737:chemistry; D009195:Peroxidase / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment
D006454:Hemoglobins; D006861:Hydrogen Peroxide; D009195:Peroxidase