Amino acids, vii

Sorm, F., SoRMOVA, Z. On proteins and amino-acids. VII. On clupein. Collect. Czech. Chem. Commun. 16. 207—213 (1951). 

The percentages of amino acids in silk fibroin which Poison et al. (224) found by direct visual and indirect photometric analysis of ninhydrin paper-partition chromatograms are shown in Table VII. The percentages obtained for alanine, glycine, and serine appear to be reasonably accurate, inasmuch as they agree closely with those found by other methods. It would be of interest to determine alanine by the microbiological method reported recently by Sauberlich and Baumann (238), in view of the widely different values found for this amino acid by the described ninhydrin-chromatographic procedure and the selec-... 

Table VII. Percentages of Amino Acids in TnSIrMtRnlnr Direct Color Analysis Silk Fibroin literature ...

S-trons)-3-amino-4-methyl-2-OXO-1 -a2etidlne-sulfonic acid (VII)... 

The alkali-soluble protein of the peel of lemons treated with hydrogen sulfide, sulfur dioxide, and sulfuric acid contained radioactive sulfur, but the fruit treated with hydrogen sulfide had a significantly lower per cent specific activity in the alkali-soluble protein fraction than did the sulfur dioxide or sulfuric acid treated fruits (Table VII). These results suggest that sulfur dioxide and sulfuric acid react with protein more directly, while hydrogen sulfide perhaps must be oxidized first, as indicated in Table III. It also appears (from Table VII) that the alkali-soluble protein may have been dismuted as the amounts isolated were less in both the hydrogen sulfide and sulfur dioxide treated fruit than in the incubated or nonincubated controls. Other evidence of dismutation has been obtained in experiments where incubation at 60° C. was accompanied by the production of free ammonia (18), and the recovery of free ammonia and six amino acids in the exudates of incubated and sulfur-dusted fruits (18). 

Purification entails use of an immunoaffinity column containing immobilized murine antifactor VII antibody. It is initially produced as an unactivated, single-chain 406 amino acid polypeptide, which is subsequently proteolytically converted into the two-chain active factor Vila complex. After sterilization by filtration, the final product is aseptically filled into its final product containers, and freeze-dried. 

A variety of radical products is observed following gamma radiolysis of the N-acetyl amino acids at 77 K (6), depending on the nature of the side chain of the parent amino acid. In the case of N-acetyl alanine, for example, the intermediates are (i) the anion radical IV (ii) the decarboxylation radical V (iii) the deamination radical VI and (iv) the alpha carbon radical VII. 

Remarks on Sections 6 and 7.-—The method here described for the synthesis of cyanohydrins—treatment of the bisulphite compound of the aldehyde with potassium cyanide—cannot be used in all cases. Concentrated solutions of hydrocyanic acid or anhydrous hydrogen cyanide are often used. The general method for the synthesis of a-amino-acids, the nitriles of which are formed by the union of ammonium cyanide with aldehydes or ketones (Strecker), is to be contrasted with that for the synthesis of a-hydroxy acids. For additional amino-acid syntheses see Chap. VII. 2, p. 276. 

Y Okada, N Ohta. Amino acids and peptides. VII. Synthesis of methionine-enkephalin using transfer hydrogenation, (cyclohexene) Chem Pharm Bull (Jpn) 30, 581, 1982. 

Mutations of COL7A1 cause a skin disease called dystrophic epidermolysis bullosa. It is a blistering disease caused by the separation of the dermal-epidermal junction. Biochemical analysis revealed the single amino acid substitution in type Vll collagen that affects the supramolecular assembly of type VII... 

Fig. 7.1 Localization of some mutations and polymorphisms reported for the calcium-sensing receptor (CASK). The relationship between the CASK gene exons (II to Vll) and the modular domains of the 1078-amino acid protein are indicated. The 610-amino acid exctracellular domain (BCD) is encoded by exons II to VI. The beginning of exon VII encodes the BCD. The remainder of exon VII encodes the transmembrane domain (TMD) of approx. 250 amino acids that includes the membrane-spanning helices TM1-TM7 (indicated by the hatched boxes), the extracellular and intracellular...

The mechanism of action of warfarin becomes apparent from the molecular details of the blood clotting process. The clotting factors VII, IX, and X require Ca ions for maximum activity. These proteins possess a novel amino acid which binds Ca ions. It is a modified form of the amino acid glutamate, as y-carboxyglutamate (Gla) which possesses two... 

Purification entails use of an immunoaffinity column containing immobilized murine antifactor VII antibody. It is initially produced as an unactivated, single chain 406 amino acid polypeptide, which is subsequently proteolytically converted into the two-chain active factor Vila complex. After sterilization by filtration, the final product is aseptically filled into its final product containers and freeze-dried. The excipients present in the product include sodium chloride, calcium chloride, polysorbate 80, mannitol and glycylglycine. When freeze-dried in the presence of these stabilizing substances and stored under refrigerated conditions, the product displays a shelf-life of at least 2 years. It has proved effective in the treatment of serious bleeding events in patients displaying anti-factor VIII or IX antibodies. 

TABLE 1 Amino acid identity of verterbrate opsin transmembrane domains I-VII... 

Figure 11. Enantiomer separation of proteinogenic a-amino acids as lheir /V(O.S)-pentafluoroprOpanoyl isopropyl esters (histidine as Vii"-ethoxycarbonyl derivative) on Chirasil-Val [20 m x 0.27 mm (i.d.) glass capillary column. 85-185"C, 0.35 bar hydrogen]. All D-enantiomers are eluted before the L-enantiomers126 111.

Coumarins are competitive inhibitors of vitamin K, which is required for the formation in the liver of the amino acid, gamma-carboxyglutamic acid. This is necessary for the synthesis of prothrombin and factors VII, IX and X (Figure 17.1). After starting treatment the anticoagulant effect is delayed until the concentration of normal coagulation factors falls (36-72 h). The effects can be reversed by vitamin K (slow maximum effect only after 3-6 h) or by whole blood or plasma (fast). Gut bacteria synthesise vitamin K and thus are an important source of this vitamin. Consequently, antibiotics can cause excessive prolongation of the prothrombin time in patients otherwise adequately controlled on warfarin. 

TABLE VII. Mobilities of Aromatic Amino Acids in Cytochrome-ca... 

Suzuki, T. Nishimura, Y. Umekawa, M. Yamamoto, Y Kawamichi, H. Furukohri, T. Evolution of phosphagen kinase VII. Isolation of glycocyamine kinase from the polychaete Neanthes diversicolor and the cDNA-derived amino acid sequences of a and chains. J. Protein Chem., 18, 13-19 (1999)... 

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