Mammalian muscle

M.p. 246-250°C (decomp.). A dipeptide present in mammalian muscle. Like anserine it contains the amino-acid -alanine which is not found in proteins. 

AChE-E (in blue) GPI-anchored dimers to plasma membranes in mammalian muscles, erythrocytes and lymphocytes. 

Nature has created a diverse array of plant and animal toxins that act at mammalian muscle and ganglionic nAChRs or invertebrate nAChRs because the critical physiological functions of these receptors make them prime targets for defensive or predatory strategies. More recently, the perceived validity of neuronal nAChR as therapeutic targets has prompted the generation of new synthetic ligands. Examples are listed in Table 1. 

Fermentation occurs naturally in various microorganisms such as bacteria, yeasts, fungi and in mammalian muscle. Yeasts were discovered to have connection with fermentation as observed by Louis Pasteur and originally defined as respiration without air. However, it does not have to always occur in anaerobic condition. For example, starch when fermented under... 

Figure 31-3. Arginine, ornithine, and proline metabolism. Reactions with solid arrows all occur in mammalian tissues. Putrescine and spermine synthesis occurs in both mammals and bacteria. Arginine phosphate of invertebrate muscle functions as a phosphagen analogous to creatine phosphate of mammalian muscle (see Figure 31-6).

Based on a study conducted with 40 healthy volunteers, Lignell reported the effect of astaxanthin on mammalian muscle function. Volunteers received one capsule of 4 mg astaxanthin each morning in association with food. No significant difference was observed between the treatment and placebo groups in any physical parameters measured. 

SERCA-type -ATPases from non-mammalian cells (SERCAMED) Sequences of SERCA-type Ca -ATPases were also obtained from Plasmodium yoelii [68], Anemia [69] and Drosophila [70], These enzymes are similar in size to the SERCAl- and SERCA2a-type Ca -ATPases from mammalian muscles, but based on their N- and C-terminal sequences they represent a distinct group. In spite of the wide philogenetic variations between them they all share a common N-term-inal sequence (MED) that differs from mammalian enzymes. None of the corresponding proteins were isolated and characterized. 

Pyrantel pamoate (Antiminth) is a agonist at the nicotinic acetylcholine receptor, and its actions result in depolarization and spastic paralysis of the helminth muscle. Its selective toxicity occurs primarily because the neuromuscular junction of helminth muscle is more sensitive to the drug than is mammalian muscle. This drug is administered orally, and because very little is absorbed, high levels are achieved in the intestinal tract. Less than 15% of the drug and its metabolites are excreted in urine. 

Pentameric structure in Torpedo electric organ and fetal mammalian muscle has two G.1 subunits and one each of Bl, 5, and 7 subunits. The stoichiometry is indicated by subscripts, eg, [(ct-l)2 Bl 5 7]. In adult muscle, the 7 subunit is replaced by an ... 

The adult nicotinic acetylcholine receptor (nAChR) is an intrinsic membrane protein with five distinct subunits (a2B T). A Cartoon of the one of five subunits of the AChR in the end plate surface of adult mammalian muscle. Each subunit contains four helical domains labeled Ml to M4. The 2 domains line the channel pore. B Cartoon of the full nAChR. The N termini of two subunits cooperate to form two distinct binding pockets for acetylcholine (ACh). These pockets occur at the (X-B and the 3-Ct subunit interfaces. 

Brown BI, Brown DH (1966) a-l,4-Glucan 6-glycosyltransferase from mammalian muscle. Methods Enzymol 8 395-403... 

In view of the close association of peptide with acid-insoluble mammalian-muscle glycogen that had been subjected to proteolysis, the possibil-... 

Gulhck, W J. and Lindstrom, J. M (1982) Structural similarities between acetylcholine receptors from fish electric organs and mammalian muscle Biochemistry 21,4563-4569. 

In initial work, L- a-phosphatidylcholine (lecithin) from egg yolk was selected as the phospholipid, and later studies compared other phospholipids and lipid extracts from meat. As the study originated from investigations of cooked meat flavor, the model system reactions were carried out in aqueous solution buffered with phosphate at an initial pH of 5.7 and concentrations of the reactants were selected to approximate their relative compositions in mammalian muscle. The reactions were carried out under pressure... 

In most mammalian muscles, amino acids are not a major fuel for oxidative metabolism, although they may be in numerous other animals. When amino acids are the fuels being combusted, they are metabolized by pathways that all ultimately feed into the Krebs cycle, where the intermediates can be fully metabolized (figure 2.3). Being at about the same oxidation state as carbohydrates, the ATP yields of amino acids during oxidation are also similar. For example, alanine oxidation... 

Hamm, R. 1962. The water binding capacity of mammalian muscle. VII. The theory of water binding (In German). Z. Lebensm. Unters. Forsch. 116 120-126. 

The regulation of glycogen phosphorylase in mammalian muscle and liver has been studied intensively. As might be expected for a pathway gov-... 

In 1979, Jette E. Kristiansen of Copenhagen, Denmark, performed extensive experiments to elaborate the effect of chlorpromazine on the permeability of the bacterial cell wall [55]. In vitro experiments were carried out with Staphylococcus aureus under the influence of chlorpromazine. Depigmentation and bacteriostatic/bactericidal effects of chlorpromazine on the microorganisms were observed. It has been shown that concentrations of chlorpromazine near the bacteriostatic value, in combination with bacterial haemolysins, could alter erythrocyte membranes of horse and rabbit blood in such a way that they become resistant to haemolysis. It was further realized that chlorpromazine in bacteriostatic concentration probably changed the transport of potassium through the bacterial membrane in the same manner as described for mammalian muscle tissue [54],... 

Chemical constitution. The approximate composition of mammalian muscle is 16-22% protein 1.5-13% lipid 0.5-13% carbohydrate 1% inorganic matter and 65-80% water (21). Poultry muscle contains less lipid. The composition of fish muscles is 15-24% protein 0.1-22% lipid 1-3% carbohydrate 0.8-2% inorganic matter and 66-84% water (21-23). 

We are so used to food that has a fibrous texture that when it is homogeneous fibres have to be added. An example is Quorn , a mycoprotein produced from Fusarium, a mycelial fungus. The threads or hyphae are about 5 pm in diameter and very thin-walled. So they hardly register as giving texture. Since they can be given a variety of flavours, it makes sense to complete the illusion with texture. One way is to align the hyphae in a shear field, add some egg albumen and fix the structure with heat. Although this does not produce a hierarchical structure, and so is more similar to chicken or fish than mammalian muscle, it is nonetheless very acceptable. 

It is well established that AChE exists in nerves and muscles in a range of globular and asymmetric molecular forms. A wide variety of sedimentation profiles have been established for AChE moleeular forms in different mammalian muscles (Massoulie and Bon, 1982). The variations seen in the ratios of these moleeular forms between different muscles are wide and eomplex. Qualitative and quantitative variations exist among different species, as well as young versus adult (Barnard et al, 1984). In the rat extensor digitorum longus (EDL, a fast twitch muscle), the... 

Berg, D.K., Keyy, R.B., Sagent, P.B., Williamson, P., Hall Z.W. (1972). Binding of a-bungarotoxin to acetycholine receptors in mammalian muscle. Proc. Natl Acad. Sci. USA 69 141-7. 

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