A clade of trypsins found in cold‐adapted fish

Abstract

A clade of trypsins, known as group III, is identified by phylogenetic analysis. These trypsins occur in fish that spend all or part of their lives at temperatures near 0 degrees C and may represent extreme psychrophilic enzymes. A principal component analysis of amino acid compositions distinguishes group III from mesophilic trypsins, as do molecular trees and multidimensional scaling of molecular sequence distances. The primary sequences of group III trypsins, in conjunction with the known structures of mesophilic trypsins, permit insight into function and mechanisms of cold adaption. The techniques employed are broadly applicable to phylogenies characterized by a markedly different, or "fast-evolving," clade. An updated lactate dehydrogenase molecular tree illustrates an additional fast-evolving clade.

Biochemical characterization of a native group III trypsin ZT from Atlantic cod (Gadus morhua)

“…This is followed by a number of sequences from fish living at temperate, subtropical or tropical climate regions. Thus, it seems clear that the group III trypsins are not only found in fish living under extreme cold conditions as previously suggested [15,42].…”

Some insights into energy metabolism for osmoregulation in fish

“…Taking trypsins as an example, this serine protease has been demonstrated to be beneficial for fish acclimatizing to cold environments. Fish trypsins show higher catalytic efficiencies than do their mammalian analogues (Schrøder Leiros et al, 2000;Roach, 2002;Gudmundsdóttir and Pálsdóttir, 2005). Hence, the metabolism of proteins and the resulting metabolites provide energy sources that are important for fish acclimating to severe environments (Aragão et al, 2004;Cara et al, 2007).…”

Applications of cold-adapted proteases in the food industry

“…It also has the highest catalytic efficiency and is by far the best characterized of the trypsin isozymes (Ásgeirsson et al, 1989;Jónsdóttir et al, 2004). Characterization of the recombinant trypsin Y polypeptide demonstrated that it is very different from classical trypsins such as trypsin I (Pálsdóttir and Guðmundsdóttir, 2004) and it may be the digestive enzyme produced under cold-shock conditions (Roach, 2002). Characterization of the recombinant trypsin Y polypeptide demonstrated that it is very different from classical trypsins such as trypsin I (Pálsdóttir and Guðmundsdóttir, 2004) and it may be the digestive enzyme produced under cold-shock conditions (Roach, 2002).…”