BLBS102-c14 BLBS102-Simpson March 21, 2012 13:17 Trim: 276mm X 219mm Printer Name: Yet to Come
14 Seafood Enzymes: Biochemical Properties and Their Impact on Quality 265
Table 14.1.Proteases from Digestive Organs of Fish and Aquatic Invertebrates
Family Enzyme Identified Species Optimum Reference
pH Temperature (◦C)
Aspartic
protease
Pepsin Pectoral rattail 3.0–3.5 45 Klomklao et al. (2007a)
Smooth hound 2.0 40 Bougatef et al. (2008)
Sea bream 3.0–3.5 45–50 Zhou et al. (2007)
European eel 2.5–3.5 35–40 Wu et al. (2009)
African coelacanth 2.0–2.5 – Tanji et al. (2007)
Chymosin Harp seal 2.2–3.5 – Shamsuzzaman and Haard (1984)
Gastricsin Hake 3.0 – Sanchez-Chiang and Ponce (1981)
Serine
protease
Trypsin Skipjack tuna 9.0 55–60 Klomklao et al. (2009a)
Tongol tuna 8.5 65 Klomklao et al. (2006a)
Yellowfin tuna 8.5 55–65 Klomklao et al. (2006b)
Pectoral rattail 8.5 45 Klomklao et al. (2009b)
Atlantic bonito 9.0 65 Klomklao et al. (2007b)
Cuttlefish 8.0 70 Balti et al. (2009)
Bluefish 9.5 55 Klomklao et al. (2007c)
Yellow tail 8.0 60 Kishimura et al. (2006a)
Brown hekeling 8.0 50 Kishimura et al. (2006a)
Spotted mackerel 8.0 60 Kishimura et al. (2006b)
Jacopever 8.0 60 Kishimura et al. (2007)
Elkhorn sculpin 8.0 50 Kishimura et al. (2007)
Sardine 8.0 60 Bougatef et al. (2007)
Walleye pollock 8.0 50 Kishimura et al. (2008)
Chymotrypsin Scallop 8.0–8.5 50–55 Chevalier et al. (1995)
Anchovy 8.0 45 Heu et al. (1995)
Monterey sardine 8.0 50 Castillo-Yanez et al. (2006)
Crucian carp 7.5–8.0 45–50 Yang et al. (2009)
Cysteine
protease
Cathepsin B Carp 6.0 45 Aranishi et al. (1997a)
Cathepsin L Jumbo squid 4.5 55 Cardenas-Lopez and Haard (2009)
Carp 5.5–60 50 Aranishi et al. (1997b)
Cathepsin S Carp 7.0 37 Pangkey et al. (2000)
Melloprotease Collagenolytic
melloprotease
Carb 7–7.5 25 Sivakumar et al. (1999)
characterized from the stomach of marine animals are pepsin,
chymosin, and gastricsin (Simpson 2000).
Pepsin, one of the major proteases found in fish viscera, has
an extracellular function as the major gastric protease. Pepsin,
secreted as a zymogen (pepsinogen), is activated by the acid in
stomach to an active form (Klomklao et al. 2007a). The activa-
tion of pepsin is initiated by the cleavage of proenzyme either
by single step or multiple steps. Nalinanon et al. (2010) reported
that pepsinogen from the stomach of albacore tuna was acti-
vated within 30–60 minutes under acidic condition, in which
protein with MW of 36.8 kDa was found as the intermediate
during activation process. Bovine pepsin is composed of a sin-
gle polypeptide chain of 321 amino acids and has a MW of
about 35 kDa (Simpson 2000). However, pepsins from marine
animals have been reported to have MWs ranging from 27 to 42
kDa. The MWs of two pepsins (I and II) from orange roughy
stomach were estimated to be approximately 33.5 kDa and
34.5 kDa, respectively (Xu et al. 1996). Sanchez-Chiang et al.
(1987) reported that the MWs of two pepsins from stomach of
salmon to be approximately 32 kDa and 27 kDa by gel filtration.
MWs of two pepsins from polar cod stomachs were estimated
by sodium dodecyl sulfate-polyacrylamide gel electrophoresis
(SDS-PAGE) to be approximately 42 kDa and 40 kDa (Aruncha-
lam and Haard 1985). The MWs of four pepsins from sea bream
stomach were determined as approximately 30 kDa by SDS-
PAGE (Zhou et al. 2007). Bougatef et al. (2008) reported that
pepsin from smooth hound stomach were estimated to be 35 kDa
using SDS-PAGE and gel filtration. The MWs of three pepsins
from the stomach of European eel were determined as 30 kDa
(Wu et al. 2009). Klomklao et al. (2007a) reported that pepsin
A and B from stomach of pectoral rattail (Coryphaenoides pec-
toralis) had apparent MWs of 35 kDa and 31 kDa, respectively,