Marine invertebrates, muscle

Earlier work involved restrained or resting fish, but recent techniques have been developed to study fish while swimming. They have also recently examined in vivo muscle energy metabolism in the cuttlefish, a marine invertebrate. ... 

Bioactive peptides as products of hydrolysis of diverse marine invertebrate (shellfish, crustacean, rotifer, etc.) proteins are the focus of current research. After much research on these muscles and byproducts, some biologically active peptides were identified and applied to useful compounds for human utilization. This chapter reviews bioactive peptides from marine invertebrates in regarding to their bioactivities. Additionally, specific characteristics of antihypertensive, anti-Alzheimer, antioxidant, antimicrobial peptide enzymatic production, methods to evaluate bioactivity capacity, bioavailability, and safety concerns of peptides are reviewed. 

As antioxidant peptides are rarely present in marine invertebrates, they must be released from the parent protein by hydrolysis with enzymes. Various enzymes have been used to release peptides from muscle proteins. To date, different muscle proteins have been extracted, hydrolysed, and their antioxidant activities studied, which is among all invertebrate muscles the most similar to vertebrate skeletal muscle. Various studies have been conducted to investigate the antioxidant properties of hydrolysates or bioactive peptides from marine invertebrate sources like oysters... 

Hemerythrin (Hr) is an 02-carrying protein found in a few phyla of marine invertebrates where it is thought to function as an O2 storage reservoir. The diiron active site reversibly binds the O2. Several reviews that discuss various aspects of Hr structure and function are available.Hr most often occurs as an octamer of essentially identical 02-binding subunits, although tetrameric, trimeric, and dimeric Hrs are also known. A monomeric counterpart, myoHr, is confined to muscle tissues of the same marine invertebrates. The structure of the myoHr subunit and active site are both very similar to those of Hr. The following discussion, therefore, applies, with very few exceptions, equally well to both Hr and myoHr. 

In most proteins the proportion of each of the different a.a. residues, calculated as a percent of the total number of residues, ranges from 0 to about 30%. In extreme cases it may even reach 50%. Cereal proteins are generally very poor in Lys. Several major grains are deficient in Thr, Leu, Met, Val, and Trp. In most collagens there are no Cys and Trp residues, while the content of Gly, Pro, and Ala is 328, 118, and 104 residues/1000 residues, respectively. Paramyosin, abundant in the muscles of marine invertebrates, is rich in Glu (20-24%), Asp (12%), Arg (12%), and Lys (9%). The antifreeze fish serum glycoproteins contain several a.a. sequences of Thr-X2-Y-X7, where X is predominantly Ala and Y a polar residue. The antifreeze proteins of type I usually contain more than 60 mol% of Ala. Thr and Y, and in various antifreeze... 

Polycyclic musks are not only present in the aqueous phase. They also tend to be adsorbed to suspended particulate matter (Winkler et al., 1998) and accumulate in riverine sediments (Lach Steffen, 1997). Additionally, Eschke et al. (1994, 1995a) reported the presence of synthetic musks in liver, muscle and fat tissues of different riverine fish species. The compounds were also found in marine invertebrates like North Sea shrimps (Rimkus Brunn, 1996). 

After a year in Meyerhof s laboratory, Ochoa, through the help of the British biophysicist A. V. Hill, moved as a research fellow to the Marine Biological Laboratory at Plymouth, England, where he studied enzymatic phosphorylation in invertebrate muscle, and in collaboration with his wife. Carmen, a study of its cozymase content. 

It is clear that the reaction of the bromo acid with the substituted amine, alanine, is associated with an inversion of the carbon atom derived from the bromo acid. This has a bearing on the configuration of octopine, a constituent of muscle of marine invertebrates. The structure of octopine (I) and the L configuration of that asymmetric carbon which is... 

Marine vertebrates, including fishes and elasmobranchs, have low zinc concentrations in tissues (i.e., 6 to 400 mg/kg DW) when compared to marine plants and invertebrates (Eisler 1980, 1981, 1984). Highest concentrations in muscle of marine fishes (20.1 to 25.0 mg/kg FW) were recorded in northern anchovy (Engraulis mordax) and Atlantic menhaden (Brevoortia tyrannus NAS 1979). 

Copper toxicity towards plants is less common than deficiency. This is in contrast to animals, where toxicity may be induced by an environmental excess of the element or with normal environmental concentrations in genetically susceptible individuals (Dawson and Price 1977). In the food chain, tolerant plant and invertebrates may accumulate copper and pose a certain risk for higher animals which consume them. Plants contain between 4 and 20 mg Cu kg dry weight, marine algae 2 to 68, fish 0.7 to 15, muscle of mammals about 10, and mammalian bones 1 to 26 (Bowen 1985). The total amount of copper in the adult human body is about 100 mg blood contains about 1 mg Cu Foods with a higher copper content include the parenchymatous internal organs of mammals, birds, and fishes especially liver, shellfish, cocoa, and red wine. The average daily copper consumption is about 0.8-1.6 mg... 

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