scholarly journals Redox equilibria of manganese peroxidase from Phanerochaetes chrysosporium: functional role of residues on the proximal side of the haem pocket

2000 ◽  
Vol 349 (1) ◽  
pp. 85 ◽  
Author(s):  
Roberto SANTUCCI ◽  
Cristiana BONGIOVANNI ◽  
Stefano MARINI ◽  
Rebecca DEL CONTE ◽  
Ming TIEN ◽  
...  
2000 ◽  
Vol 349 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Roberto SANTUCCI ◽  
Cristiana BONGIOVANNI ◽  
Stefano MARINI ◽  
Rebecca DEL CONTE ◽  
Ming TIEN ◽  
...  

Redox potentials of recombinant manganese peroxidase from Phanerochaetes chrysosporium have been measured by cyclic voltammetry as a function of pH, between pH 4.5 and pH 10.5. They display a bimodal behaviour (characterized by an ‘alkaline’ and an ‘acid’ transition), which indicates that (at least) two protonating groups change their pKb values upon reduction (and/or oxidation) of the iron atom in haem. Analogous measurements have been carried out on four site-directed mutants involving residues in close proximity to the proximal ligand, His173, in order to investigate the role played by residues of the proximal haem pocket on the redox properties of this enzyme. Results obtained suggest that the protonation state of N∆ of the proximal imidazole group is redox-linked and that it is crucial in regulating the ‘alkaline’ transition. On the other hand, none of the proximal mutants alters the ‘acid’ transition, suggesting that it is modulated by groups located in a different portion of the protein.


2009 ◽  
Vol 221 (03) ◽  
Author(s):  
B Steiger ◽  
I Leuschner ◽  
D Denkhaus ◽  
D von Schweinitz ◽  
T Pietsch
Keyword(s):  

2020 ◽  
Vol 9 (2) ◽  
pp. 78-88
Author(s):  
Mulugeta Mulat ◽  
Raksha Anand ◽  
Fazlurrahman Khan

The diversity of indole concerning its production and functional role has increased in both prokaryotic and eukaryotic systems. The bacterial species produce indole and use it as a signaling molecule at interspecies, intraspecies, and even at an interkingdom level for controlling the capability of drug resistance, level of virulence, and biofilm formation. Numerous indole derivatives have been found to play an important role in the different systems and are reported to occur in various bacteria, plants, human, and plant pathogens. Indole and its derivatives have been recognized for a defensive role against pests and insects in the plant kingdom. These indole derivatives are produced as a result of the breakdown of glucosinolate products at the time of insect attack or physical damages. Apart from the defensive role of these products, in plants, they also exhibit several other secondary responses that may contribute directly or indirectly to the growth and development. The present review summarized recent signs of progress on the functional properties of indole and its derivatives in different plant systems. The molecular mechanism involved in the defensive role played by indole as well as its’ derivative in the plants has also been explained. Furthermore, the perspectives of indole and its derivatives (natural or synthetic) in understanding the involvement of these compounds in diverse plants have also been discussed.


Sign in / Sign up

Export Citation Format

Share Document