Shann Tzong Jiang earned his Master Degree from Tokyo University of Fisheries, Japan, and PhD from University of Rhode Island, USA. He is a Fellow of the International Academy of Food Science & Technology, and National Endowed Chair Professor of the Ministry of Education of Taiwan. Currently he is working at the Department of Food Science, National Taiwan Ocean University, and at Providence University as Senior Vice President. He has published more than 170 papers in reputed journals and has been serving as Editorial Board Member of several repute journals.
There are various angiotension-I converting enzyme inhibitors (ACEIs) have been investigated for palliating the hypertension. To produce ACE inhibitor peptides, 15 fragments of DNA sequences encoded well-known ACEI peptides from fish protein hydrolysates, GW, IW, KW, LF, MF, VW, VY, YL, GPL, GPM, IKW, VY, IRPVQ, IWHHT and IYPRY, were designed as a combinative DNA encoded a fusion ACEI polypeptide which could be hydrolyzed into individual ACEI peptides by chymotrypsin. The combinative DNA consisted of 234 nucleotides was cloned into the pET-23a(+) expression vector and then transformed into E. coli BL21(DE3) expression host. After 8 h induction by 0.1 mM isopropyl-β-D-thiogalactopyranoside, high activity of the recombinant fusion ACEI polypeptide was expressed. After sonication to disrupt the cell wall, the recombinant fusion ACEI polypeptide could be purified using Ni Sepharose™ 6 Fast Flow. The IC50 value of recombinant ACEI polypeptide is 11.82 μM. After chymotrypsin digestion, a 74-fold increase of ACEI activity (0.16 μM) was obtained, which was equivalent to 0.022 μM of captopril.The ACEI activity of the chymotrypsin hydrolysate increased about 74-fold activity after hydrolysis. It can be used in the health food for the prevention of high blood pressure, and even the development of drugs for medication in the future.
Su Mei Wu earned her Master Degree from Marine Biology Institute of National Taiwan University, and PhD from National Normal University, both are local in Taiwan. She is a Fellow of the Institute of Aquatic Biosciences of Chiayi University. She has published more than 85 papers in reputed journals and has been serving as reviewer of several repute journals. Her major include aquatic toxicology and fish physiology. Teaching programs have “Stress and Fish”, “Fish Endocrinology”, “Environment Sciences”
Salinity change is one of stressor on freshwater fish, and fish will regulate osmolality balance to acclimate seawater environment. The ionic/osmotic regulation mechanisms include the morphological modification of gill MR cells and stimulation of both the expression and activity of ion transporters. All need energy to active. The Previous study had found that the GR cells were initially stimulated to provide promot energy for neighboring MR cells that trigger ion-secretion mechanism. Therefore, the objective of this study is to explore the energy metabolism of tilapia (Oreochromis mossambicus) upon acute salinity exposure in gills and liver. There are four groups of treatments in the present study, which are included: Fish were adapted in the brackish water (20 ‰) for 1 or 2 days and then transferred to 28 ‰ seawater (respectively to BW1d-SW; BW2d-SW representation); Fish were transferred directly to 20 ‰ brackish water group (FW-BW); Fish were transferred directly to the group of 28 ‰ seawater seawater (FW-SW). The study was to compare the biochemical reactions of the glycogen metabolism between the gills and hepatic tissues. Results showed that the glycogen phosphorylase (GP) activity was significantly increased at 1 hour after acute salinity exposure. It was interesting to find that the BW1d-SW and BW2d-SW groups, although their osmolality increased following the salinity change, but they eventually recovered to the normal level soon. Furthermore, the plasma ions content of FW-SW groups elevated over following the time of SW exposure. Comparatively, it showed a peak within 1 hour and recovery as control on the BW1d-SW and BW2d-SW groups. According to the data, Author suggested that the GP activity changes have potential as an effective indicator upon salinity stress.