Quality improvement of threadfin bream (Nemipterus virgatus) surimi-gel using soy protein as a natural food additive.

Previously, we identified sarcoplasmic serine proteinase (SSP) as a modori-inducing proteinase from threadfin bream belly muscle. In this study, we investigated the autolytic activity of commercial threadfin bream surimi under modori-inducing conditions. High autolytic activity was detected in commercial surimi and was inhibited by a soybean trypsin inhibitor, indicating that SSP still remained in the commercial surimi.

Transcriptional regulation of the Japanese flounder Cu,Zn-SOD (Jfsod1) gene in RAW264.7 cells during oxidative stress caused by causative bacteria of edwardsiellosis.

Edwardsiellosis is one of the most important bacterial diseases in fish, sometimes causing extensive economic losses in the aquaculture industry. Our previous studies demonstrated that the Cu,Zn-SOD (sod1) activity has significantly increased in Japanese flounder, Paralichthys olivaceus, hepatopancreas infected by causative bacteria of edwardsiellosis Edwardsiella tarda NUF251. In this study, NUF251 stimulated intracellular superoxide radical production in mouse macrophage RAW264.

Identification of a Tissue Inhibitor of Metalloproteinase-2: An Endogenous Inhibitor of -Inducing Insoluble Metalloproteinase from Yellowtail Muscle.

The existence of an endogenous protease inhibitor (EPI) was expected from the comparison of the gel properties between washed and nonwashed yellowtail gels. A possible candidate, tissue inhibitor of metalloproteinase-2 (TIMP-2), was partially purified from the soluble fraction of yellowtail muscle, and an 18 kDa protein band was detected by sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) under nonreducing conditions and western blot analysis. Its N-terminal amino acid sequence was determined as XSXSPAHPQQAF, with high homology to TIMP-2 from other fish species, suggesting that it was identified as yellowtail TIMP-2.

Cloning, DNA sequence, and expression of flagellins from high and low virulence strains of Edwardsiella tarda and their macrophage-stimulating activities.

Edwardsiella tarda is a causative pathogen of edwardsiellosis in fish. Our previous studies on high (NUF251) and low (NUF194) virulent strains of E. tarda demonstrated that NUF251 strain induced significantly higher levels of NO and TNF-α from fish and mouse macrophages than NUF194 strain.

Identification and Characterization of the Larval Settlement Pheromone Protein Components in Adult Shells of : A Novel Function of Shell Matrix Proteins.

The global decline of natural oyster populations emphasizes the need to improve our understanding of their biology. Understanding the role of chemical cues from conspecifics on how oysters occupy appropriate substrata is crucial to learning about their evolution, population dynamics, and chemical communication. Here, a novel role of a macromolecular assembly of shell matrix proteins which act as Settlement Pheromone Protein Components in adult shells is demonstrated as the biological cue responsible for gregarious settlement on conspecifics.

Impact of different enzymes on biofilm formation and mussel settlement.

Enzymes have been known to impact the biofilm forming capacity. However, how the enzymes mediate the biofilm formation and macrofouling remains little known. Here, we investigated the effects of the three kinds of proteases, four kinds of glycosidases and one kind of lipase on the detachment of biofilms of Shewanella marisflavi ECSMB14101, identified biofilm total proteins response to enzyme treatments, and then tested the effects of biofilms treated with enzymes on the settlement of the mussel Mytilus coruscus plantigrades.

A bacterial polysaccharide biosynthesis-related gene inversely regulates larval settlement and metamorphosis of .

Larval settlement and metamorphosis is essential for the development of marine invertebrates. Although polysaccharides are involved in larval settlement and metamorphosis of , the molecular basis of polysaccharides underlying this progression remains largely unknown. Here, the roles of the polysaccharide biosynthesis-related gene of ECSMB14103 in the regulation of larval settlement and metamorphosis were examined by gene-knockout technique.

Identification of a modori-inducing proteinase in the threadfin bream: Molecular cloning, tissue distribution and proteinase leakage from viscera during ice storage.

Previously we purified and characterized a sarcoplasmic serine proteinase (SSP) from the belly muscle of the threadfin bream as a modori-inducing proteinase. In our attempt to clarify the structure and physiological functions of SSP, we successfully cloned the full-length cDNA of SSP (ORF 726 bp). The deduced amino acid sequence of SSP (241 residues) was highly homologous to fish trypsinogen.

The Flagellar Gene Regulates Biofilm Formation and Mussel Larval Settlement and Metamorphosis.

Biofilms are critical components of most marine systems and provide biochemical cues that can significantly impact overall community composition. Although progress has been made in the bacteria-animal interaction, the molecular basis of modulation of settlement and metamorphosis in most marine animals by bacteria is poorly understood. Here, showing inducing activity on mussel settlement and metamorphosis was chosen as a model to clarify the mechanism that regulates the bacteria-mussel interaction.

An ɑ-adrenergic receptor is involved in larval metamorphosis in the mussel, .

Metamorphosis is crucial in the life-cycle transition between the larval and juvenile stages of marine invertebrates. Although a number of agonists and antagonists of the adrenergic receptor (AR) are known to regulate larval metamorphosis in (Mc), the molecular basis of the modulation of larval metamorphosis by the AR gene in this species remains elusive. Herein, the role of the AR gene in larval metamorphosis using the RNA interference technique was examined.

Purification and characterization of a sarcoplasmic serine proteinase from threadfin bream Nemipterus virgatus muscle.

A sarcoplasmic serine proteinase (SSP) was purified from threadfin bream (Nemipterus virgatus) belly muscle by ammonium sulfate precipitation and a series of chromatographies including Q-Sepharose, Phenyl Sepharose and Superdex 200. The SSP was purified 1967 folds with a yield of 4.8%.

Polyurethane, epoxy resin and polydimethylsiloxane altered biofilm formation and mussel settlement.

In many environments, biofilms are a major mode and an emergent form of microbial life. Biofilms play crucial roles in biogeochemical cycling and invertebrate recruitment in marine environments. However, relatively little is known about how marine biofilms form on different substrata and about how these biofilms impact invertebrate recruitment.

Elevated Seawater Temperatures Decrease Microbial Diversity in the Gut of .

The gut microbial community is critical for the host immune system, and in recent years, it has been extensively studied in vertebrates using 'omic' technologies. In contrast, knowledge about how the interactions between water temperature and diet affect the gut microbiota of marine invertebrates that do not thermoregulate is much less studied. In the present study, the effect of elevated seawater temperature and diet ( and var.

Purification and Characterization of Cathepsin B from the Muscle of Horse Mackerel Trachurus japonicus.

An endogenous protease in fish muscle, cathepsin B, was partially purified and characterized from horse mackerel meat. On SDS-PAGE of the purified enzyme under reducing conditions, main protein bands were detected at 28 and 6 kDa and their respective N-terminal sequences showed high homology to heavy and light chains of cathepsin B from other species. This suggested that horse mackerel cathepsin B formed two-chain forms, similar to mammalian cathepsin Bs.

Molecular cloning and tissue distribution of hyaluronan binding protein 2 (HABP2) in red sea bream Pagrus major.

Previously we have isolated a novel gelatinolytic serine proteinase, named G1, from the muscle and the plasma of red sea bream. In order to clarify the structure and function of G1, we cloned the full-length cDNA of G1 from the hepatopancreas of red sea bream. G1 cDNA encoded 633 amino acids with a secretory signal sequence at N-terminus, three epidermal growth factor-like domains, a kringle domain, and a trypsin-like serine protease domain.

Purification, molecular cloning, and some properties of a manganese-containing superoxide dismutase from Japanese flounder (Paralichthys olivaceus).

Manganese-superoxide dismutase (Mn-SOD) from Japanese flounder (Paralichthys olivaceus) hepatopancreas has been purified with high purification (781-fold) and recovery (10.8%). The molecular mass of the purified enzyme was estimated to be 26kDa by SDS-PAGE under reducing conditions.

Purification and characterization of pepsinogens and pepsins from the stomach of rice field eel (Monopterus albus Zuiew).

Three pepsinogens (PG1, PG2, and PG3) were highly purified from the stomach of freshwater fish rice field eel (Monopterus albus Zuiew) by ammonium sulfate fractionation and chromatographies on DEAE-Sephacel, Sephacryl S-200 HR. The molecular masses of the three purified PGs were all estimated as 36 kDa using SDS-PAGE. Two-dimensional gel electrophoresis (2D-PAGE) showed that pI values of the three PGs were 5.

Extracellular products from virulent strain of Edwardsiella tarda stimulate mouse macrophages (RAW264.7) to produce nitric oxide (NO) and tumor necrosis factor (TNF)-alpha.

We have previously found that high virulent strain (NUF251) of Edwardsiella tarda, but not low virulent strain (NUF194), was able to survive and multiply within Japanese flounder (Paralichthys olivaceus) peritoneal macrophages. Further studies demonstrated that NUF251 induced much higher levels of NO and TNF-alpha productions than NUF194 in both Japanese flounder peritoneal macrophages and mouse macrophage cell line RAW264.7.

Biochemical characterization of chymotrypsins from the hepatopancreas of Japanese sea bass (Lateolabrax japonicus).

Two chymotrypsins (chymotrypsins A and B) have been purified to homogeneity from the hepatopancreas of Japanese sea bass ( Lateolabrax japonicus ) by ammonium sulfate fractionation and chromatographies on DEAE-Sepharose and Phenyl-Sepharose. Two-dimensional electrophoresis (2-DE) analysis revealed that the molecular masses of chymotrypsins A and B were approximately 27.0 and 27.

Comparative analysis of the production of nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) from macrophages exposed to high virulent and low virulent strains of Edwardsiella tarda.

We previously reported that high virulent strain (NUF251) of Edwardsiella tarda has an ability to prevent the production of reactive oxygen species by macrophages, and is even capable of surviving and multiplying within Japanese flounder (Paralichthys olivaceus) peritoneal macrophages, whereas the low virulent strain (NUF194) has no such ability. In this study, we found that NUF251 and NUF194 induced NO and TNF-alpha production from Japanese flounder peritoneal macrophages, and NUF251 caused faster induction of NO release and much higher level of TNF-alpha production than NUF194. In addition, similar differences between two strains in terms of the induction of NO and TNF-alpha production were also observed in mouse macrophage cell line RAW264.

Comparison of the responses of peritoneal macrophages from Japanese flounder (Paralichthys olivaceus) against high virulent and low virulent strains of Edwardsiella tarda.

In vivo infection studies in Japanese flounder (Paralichthys olivaceus) demonstrated that the number of viable cells of the virulent strain (NUF251) of Edwardsiella tarda increased gradually in kidney and hepato-pancreas after intraperitoneal injection, but the low virulent strain (NUF194) did not. To gain insight into the virulence factors of E. tarda, in vitro responses of Japanese flounder (P.

Sequential immunization with V3 peptides from primary human immunodeficiency virus type 1 produces cross-neutralizing antibodies against primary isolates with a matching narrow-neutralization sequence motif.

An antibody response capable of neutralizing not only homologous but also heterologous forms of the CXCR4-tropic human immunodeficiency virus type 1 (HIV-1) MNp and CCR5-tropic primary isolate HIV-1 JR-CSF was achieved through sequential immunization with a combination of synthetic peptides representing HIV-1 Env V3 sequences from field and laboratory HIV-1 clade B isolates. In contrast, repeated immunization with a single V3 peptide generated antibodies that neutralized only type-specific laboratory-adapted homologous viruses. To determine whether the cross-neutralization response could be attributed to a cross-reactive antibody in the immunized animals, we isolated a monoclonal antibody, C25, which neutralized the heterologous primary viruses of HIV-1 clade B.

Concentration-dependent suppressive effect of shrimp head protein hydrolysate on dehydration-induced denaturation of lizardfish myofibrils.

To utilize fishery waste products as functional food material, the shrimp head protein hydrolysate (SHPH) was produced from three species of shrimp wastes, Northern pink shrimp, Endeavour shrimp and black tiger shrimp, by enzymatic hydrolysis. The SHPH was used as a natural food preservative by adding to lizardfish myofibrils at concentrations ranging from 2.5% to 10%.

A novel type of myofibril-bound serine protease from white croaker (Argyrosomus argentatus).

Myofibril-bound serine protease (MBSP) was purified from the myofibril fraction of white croaker (Argyrosomus argentatus) muscle and its enzymatic properties were compared with other fish MBSPs. White croaker MBSP was extracted by the heat treatment of myofibrils and then purified by a series of column chromatographies on Q-Sepharose, Sephacryl S-300, hydroxyapatite and Benzamidine Sepharose. The purified MBSP migrated as a single protein band at 67 kDa in SDS-PAGE under both reducing and non-reducing conditions.

A novel serine protease complexed with alpha2-macroglobulin from skeletal muscle of lizard fish (Saurida undosquamis).

A novel fish muscle serine protease named muscle soluble serine protease (MSSP) was purified from the soluble fraction of lizard fish (Saurida undosquamis: Synodontidae) muscle by ammonium sulfate fractionation followed by four steps of column chromatographies. In native-PAGE, the purified enzyme appeared as a single band with an estimated mol. mass of approximately 380 kDa by gel filtration.