4.7 Article

Multiple putative methemoglobin reductases in C. reinhardtii may support enzymatic functions for its multiple hemoglobins

Journal

INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
Volume 171, Issue -, Pages 465-479

Publisher

ELSEVIER
DOI: 10.1016/j.ijbiomac.2021.01.023

Keywords

Algal hemoglobins and reductases; Methemoglobin reduction; NO dioxygenase

Funding

  1. Department of Biotechnology (DBT), Government of India [BT/PR11275/GBD/27/150/2008]
  2. UGC, Government of India
  3. DST-FIST of Government of India [SR/FST/PS-I/2019/68]
  4. Council of Scientific and Industrial Research (CSIR)
  5. Defence Research and Development Organization (DRDO) [LSRB-317/SHDD/2017]
  6. UGC (SAP programme)
  7. Department of Science and Technology (DST) (PURSE programme)
  8. University of Delhi (RD programme)

Ask authors/readers for more resources

Hemoglobins may have alternative physiological functions aside from oxygen transport, such as nitric oxide dioxygenase. Algal hemoglobins are expected to have multiple putative methemoglobin reductases to augment their physiological functions. The identified putative methemoglobin reductases can reduce algal methemoglobins in a nonspecific manner under in vitro conditions.
The ubiquitous nature of hemoglobins, their presence in multiple forms and low cellular expression in organisms suggests alternative physiological functions of hemoglobins in addition to oxygen transport and storage. Previous research has proposed enzymatic function of hemoglobins such as nitric oxide dioxygenase, nitrite reductase and hydroxylamine reductase. In all these enzymatic functions, active ferrous form of hemoglobin is converted to ferric form and reconversion of ferric to ferrous through reduction partners is under active investigation. The model alga C. reinhardtii contains multiple globins and is thus expected to have multiple putative methemoglobin reductases to augment the physiological functions of the novel hemoglobins. In this regard, three putative methemoglobin reductases and three algal hemoglobins were characterized. Our results signify that the identified putative methemoglobin reductases can reduce algal methemoglobins in a nonspecific manner under in vitro conditions. Enzyme kinetics of two putative methemoglobin reductases with methemoglobins as substrates and in silico analysis support interaction between the hemoglobins and the two reduction partners as also observed in vitro. Our investigation on algal methemoglobin reductases underpins the valuable chemistry of nitric oxide with the newly discovered hemoglobins to ensure their physiological relevance, with multiple hemoglobins probably necessitating the presence of multiple reductases. (C) 2021 Elsevier B.V. All rights reserved.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.7
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available