Fish peptides

Kim et ah (1999) and Jung et ah (2005b) reported that fish peptides can accelerate calcium absorption. Under many conditions, dietary calcium becomes unavailable for absorption due to the formation of insoluble compounds inside the dietary tract, and inadequate dietary calcium is associated with a number of common and chronic diseases including osteoporosis, osteoarthritis, cardiovascular disease (hypertension and stroke), diabetes, obesity, and cancer (Anderson and Gamer,... 

Kim et al. (1999) and Jung et al. (2005) reported that fish peptides are capable of accelerating calcium absorption. Further, researchers have identified that fish protein hydrolysates possess hormone-like peptides and growth factors to accelerate calcium absorption (Fouchereau-Peron et al., 1999). These peptides are capable of binding to cell surface receptors on osteoclasts and involved mainly in calcium metabolism by decreasing the number of osteoclasts. Therefore, these peptides could be used in the treatment of osteoporosis and Paget s disease (Table 15.3). 

In general, nonconventional protein foods must be competitive with conventional plant and animal protein sources on the bases of cost delivered to the consumer, nutritional value to humans or animals, functional value in foods, sensory quality, and social and cultural acceptability. Also, requirements of regulatory agencies in different countries for freedom from toxins or toxic residues in single-cell protein products, toxic glycosides in leaf protein products, pathogenic microorganisms, heavy metals and toxins in fish protein concentrates, or inhibitory or toxic peptide components in synthetic peptides must be met before new nonconventional food or feed protein products can be marketed. 

A unique family of O-linked glycoproteins permits fish to live in the icy seawater of the Arctic and Antarctic regions where water temperature may reach as low as — 1.9°C. Antifreeze glycoproteins (AFGPs) are found in the blood of nearly all Antarctic fish and at least five Arctic fish. These glycoproteins have the peptide structure... 

Nitrogen sources include proteins, such as casein, zein, lactalbumin protein hydrolyzates such proteoses, peptones, peptides, and commercially available materials, such as N-Z Amine which is understood to be a casein hydrolyzate also corn steep liquor, soybean meal, gluten, cottonseed meal, fish meal, meat extracts, stick liquor, liver cake, yeast extracts and distillers solubles amino acids, urea, ammonium and nitrate salts. Such inorganic elements as sodium, potassium, calcium and magnesium and chlorides, sulfates, phosphates and combinations of these anions and cations in the form of mineral salts may be advantageously used in the fermentation. 

Between 6 and 10 homologous peptides have been extensively characterized for each toxin class. Although uj- and a-conotoxins have been isolated from several fish-hunting Conus species, x-conotoxins have so far been isolated only from C. geographus venom. 

Peptides in the a-conotoxin family are inhibitors of nicotinic acetylcholine receptors. They were first isolated from C. geographus venom as components which cause paralysis in mice and fish when injected intraperitoneally (27). Early physiological experiments (28) indicated that a-conotoxins GI, GII, and GIA (see Table III) all act at the muscle end plate region. Mini end-plate potentials and end plate potentials evoked in response to nerve stimulation are inhibited in the presence of a-conotoxins in the nM to pM range. a-Conotoxin GI was subsequently shown to compete with rf-tubocurarine and a-bungarotoxin for the acetylcholine receptor (29). 

Proteinaceous phytochemicals can contain toxic epitopes that elicit defense responses for example gliaden and glutein peptides which cause celiac disease and other mucosal disorders (Tighe and Ciclitira, 1995 Van de Wal et al, 1999). The mucosal inflammation caused by feeding carnivorous Atlantic salmon diets with soybean meal decreases rates of nutrient absorption (Nordrum et al, 2000), whereas the detrimental influence of such diets is much less pronounced when fed to omnivorous fish, such as catfish and tilapia. 

Jawless fish (Cambrian) As above second hydroxylation giving norepinephrine and amidated peptides copper chemistry in vesicles Recovery additionally by hydrolysis Zinc enzymes... 

As well as protein expression analysis, proteomics in its broadest sense also includes protein-protein interaction mapping. This can range from small studies using a single protein or peptide to fish ouf any proteins that interact with it... 

The type of proteinaceous binder was correctly identified in all model samples. In only one case (S10), the animal glue was additionally identified, although the restorer who prepared these model samples declared that the sample contained only egg binder. It is possible that this sample was contaminated during its preparation or during laboratory treatment. The results indicate that this method does not allow reliable identification of the presence of individual egg yolk and egg white most probably it is caused by the presence of a trace of egg white that is always present in the egg yolk preparations (and vice versa) and can be detected by the highly sensitive PMM method. The identification of individual types of animal glues will never be reliable by MALDI-TOF mass spectrometry because of their similar composition the application of ESI (electrospray ionisation)-MS/MS (Section 6.5) could possibly overcome this problem. Only the fish glue, whose peptide... 

Bacterial botulinum toxin blocks presynaptic acetylcholine release 725 Snake, scorpion, spider, fish and snail peptide venoms act on multiple molecular targets at the neuromuscular junction 727 Electrolyte imbalances alter the voltage sensitivity of muscle ion channels 728... 

The crude extract from Guam specimens inhibits fishes and a mixture of cyclic peptides containing laxaphycin A deters feeding by the fish Scarus schiegeii, the sea urchin Diadema savignyi, and the crab Leptodius sp. (Pennings et al. 1997)... 

In the field of fresh water plankton chemical ecology microcystins from cyanobacteria have stimulated much research and discussion. A critical reflection on the ecological function of these non-ribosomal peptides has recently been published (Babica et al. 2006). Surveys of methods for the quantification of these peptides (McElhiney and Lawton 2005 Msagati et al. 2006) and on the effects on fish (Malbrouck and Kestemont 2006) can be found as well. 

A database search reveals that YPClp and YDClp are not homologous to any proteins with known functions, but are homologous to putative proteins from Arabidoposis, C. elegans, peptides deduced from EST sequences of human, mouse, pig, zebra fish, and human genomic sequences. A human homologue has been identified and its cDNA has been cloned. Preliminary results show that this human homologue is also an alkaline ceramidase that selectively hydrolyzes phytoCer. 

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