Acid Proteinases from Antarctic Krill, Euphausia superb: Partial Purification and Some Properties

• Published in: Journal of Food Science
• Main Authors: KIMOTO, K., THANH, V. V., MURAKAMI, K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1981
• Subjects: Antarctic; Antarc*; Antarctic Krill; Euphausia superba
• Online Access: http://dx.doi.org/10.1111/j.1365-2621.1981.tb04510.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2621.1981.tb04510.x; http://onlinelibrary.wiley.com/wol1/doi/10.1111/j.1365-2621.1981.tb04510.x/fullpdf

ABSTRACT The presence of neutral and alkaline proteinases in the extract from Antarctic krill, Euphausia superba was confirmed. In addition to these enzymes, acid proteinases were found in the extract from E. superba and the two major acid proteinases, A and B, were purified 80–140 fold. The molecular weights of acid proteinases A and B were estimated by gel filtration on Sephadex G‐100 to be approximately 45,000 and 64,000, respectively. The optimal pH of enzymes A and B was 3.0 toward hemoglobin. They were partially inhibited by acid proteinase specific reagents: diazoacethyl‐DL‐norleucine methylester (DAN) and 1,2epoxy‐3‐( p ‐nitrophenoxy) propane (EPNP). However, enzyme B was less sensitive to pepstatin while enzyme A was inhibited by pepstatin like almost all other acid proteinases.