From yeast extract

Several amino acids in AGSl within the nucleotidebinding/hydrolysis motifs differ from their counterparts in Ras, and mutation of these residues in Ras leads to constitutive activity (Barbacid 1987 Feig and Cooper 1988), suggesting that AGSl may be constitutively active. AGS 1 is active in yeast-based assays without any apparent stimuli, and AGS 1 purified from yeast extracts is largely GTP bound (Cismowski et al. 2000). It is presently unclear whether these amino acid variations are sufficient to render AGS 1 constitutively active in mammalian cells or how posttranslational modifications of AGS 1 influence ifs level of basal and stimulated activity. 

IT Corporation performed laboratory-scale testing of the use of micronutrients from yeast extract to encourage biological polishing after thermally enhanced fluid injection with vacuum extraction (FIVE) for coral sand contaminated with petroleum hydrocarbons. The commercial availability of this technology is unknown. 

Elicitation in conjunction with an in situ extraction phase altered alkaloid production patterns. In particular, elicitors isolated from yeast extract can accelerate the production and the levels of benzophenanthridine alkaloids in E. 

Vitamin M Vitamin M is also called pteroylglutaminic add or folic acid. It was isolated from yeast extract by Wills in 1930. Its structure was described by Anger in 1946. Folic add is made up of pteridine + p-aminobenzoic add + glutamic add. There are several known derivatives, called folates, which are capable of mutual restructuring. The coenzyme tetrahydrofolic acid, which plays a role in many biochemical reactions, is formed with the help of Bi2. Around 50% of total body folate are stored in the liver. A folate-binding protein (FBP) is available for transport. Folate undergoes enterohepatic circulation. The release of folate from the liver cells is stimulated by alcohol, which increases urine excretion. Folate deficiency (e.g. in the case of alcohol abuse) is accompanied by the development of macrocytosis. 

The carbon skeleton of the phytoalexins of the Maloideae is formed by BIS that was cloned from yeast-extract-treated cell cultures of S. aucuparia and functionally expressed in E. coli (42) Addition of the elicitor to the cell cultures... 

Buchners fermentation of sugar from yeast extracts Sumner s crystallization of urease Flemming s discovery of chromosomes Mendel s characterization of genes Miescher s isolation of nucleic acids Watson and Crick s stmcture of DNA... 

Furthermore, a multisubunit TAF complex was purified from yeast extracts using GST-TBP as a ligand for affinity chromatography (Reese et al., 1994). The use of epitope tag and immunoprecipitation also led to the isolation of TBP-TAFs complex from yeast extract (Poon et al.,... 

B-factor [adenosine-3 -(monobutyl phosphate), 3 -AMP-monobutyl ester]. C,4H22N50,P, Mr 403.34, Na salt powder, mp. 182-186°C. Substance isolated from yeast extracts that induce in Nocardia sp. rifam-ycin B production in the concentration range of 2-30 ng/ml. The regulation of rifamycin biosynthesis occurs prior to the incorporation of 3-aminohydroxy-... 

Halophilic and halotolerant microorganisms generally prefer uptake of compatible solutes from the medium over de novo synthesis. For this reason organisms grown in complex media will normally accumulate compatible solutes, such as trehalose and glycine betaine, from yeast extract. Presumably, the same preference for solute uptake occurs in the environment where compatible solutes are available from cell death. 

A glucan from yeast extract containing 3-, 6-, and 3,6-linked glucosyl residues was shown to elicit formation of glyceollin in soybeans Glycine max, Fabaceae). The yeast-derived elicitor stimulates accumulation of this isoflavone when as little as 15 ng of the elicitor is applied to soybean cotyledons (Hahn and Albersheim, 1978). 

Hahn, M. G. and P. Albersheim, Host-pathogen interactions. XIV. Isolation and partial characterization of an elicitor from yeast extract. Plant Physiol, 62, 107-111 (1978). 

This reaction is the first committed step in the conversion of IMP to AMP and represents a branch point in the synthesis of IMP, the end product of tie novo purine biosynthesis. Although it had been known for some time that nitrogen from dietary components is rapidly incorporated into cellular AMP, especially into the 6-amino group 1, 2), specific s3mthesis of AMP from IMP was not demonstrated until 1955. Abrams and Bentley (3) showed that the conversion occurred in rabbit bone marrow while Lieberman (4) demonstrated it in Escherichia coli. Carter and Cohen (5, 6) isolated and characterized adenylosuccinate from yeast extracts. Lieberman (4) demonstrated that adenylosuccinate could be formed reversibly from IMP and aspartate by a partially purified enzyme fraction fromE. coli. 

A regulator factor able to induce the synthesis of rifamycin B in a nonproducing mutant of A. mediienanei was isolated from yeast extracts (20). It was named B factor and identified as 3 -(l-bucylphosphoryl) adenosine. B factor appears to regulate the production of the rifamycin precursor 3-amino-5 hydroxybenzoic acid, since addition of the lat-... 

Only young, vigorously growing cultures should be used for the evaluation of nitrogen and carbon utilization profiles. Furthermore, cultures should be previously transferred from yeast extract-malt extract medium... 

As the study of CoA developed, it became apparent that the coenzyme was involved in reactions whereby acetate was activated by ATP and subsequently transferred to various acetyl acceptors. In pigeon liver extracts it was shown that acetate could be activated by ATP in the presence of CoA to acetylate sulfanilamide, PABA, histamine, glucosamine, to synthesize acetoacetic acid and citrate. Acetyl phosphate, which has been demonstrated to be a product of pyruvate metabolism in several bacteria and could theoretically be considered to be an intermediate in these reactions, was found to be unable to replace acetate and ATP in animal tissues. Eventually it was shown that there is present in certain bacteria an enzyme, phosphotransacetylase, which could convert acetyl phosphate to a reactive product which was thought to be acetyl-CoA.i 194 isolation of acetyl-CoA from yeast extract by Lynen and Reichert confirmed the idea that acetyl-CA is the reactive 2-carbon unit in these reactions. Stadtman has demonstrated that acetyl-CoA is indeed the product of the action of phosphotransacetylase. Lipmann has recently... 

Reduction of L-aspartyl /3-semialdehyde to L-homoserine is catalyzed by homoserine dehydrogenase (Fig. 3, reaction 3). Both DPNH and TPNH can serve as hydrogen donors. However, DPNH is about three times as effective as TPNH. This dehydrogenase has also been purified from yeast extracts about a hundredfold by heat treatment, precipitation at pH 4.6 with ammonium sulfate, followed by chromatography on a calcium phosphate gel column. 

Proteolytic enzymes in yeast have long been known (Willstatter and Grassmann (1). As early as 1917, K. G. Dernby (2) described three types of proteolytic enzymes in extracts and autolysates of yeast. More recently, four different proteinases have been characterized and purified from yeast extracts some of their properties are summarized in Table I. In this paper, recent work on the "acid proteinase A and its specific inhibitors from yeast is described as well as possible biological functions of this proteinase A-inhibitor system. 

Proteinase A was purified from yeast extracts, activated by incubation at pH 5, by repeated chromatography on DEAE-Sephadex followed by alcohol precipitation, as described by Hata et al. (3). The enzyme could be further purified in our laboratory by affinity chromatography of the partially purified enzyme, using the specific proteinase A-inhibitor I, bound to activated CH-Sepharose 4B as the stationary phase. The pattern of elution by 6 M urea from the affinity column is shown in Figure 1 the peaks of hemoglobinhydrolyzing activity (i.e. proteinase A activity) and protein concentration coincide. Table II summarizes the present purification procedure for proteinase A. Work on further purification and characterization of the enzyme is in progress. 

Riboflavin is another highly water-soluble vitamin and was isolated from yeast extract in 1933. It has a bright yellow colour and excess vitamin is rapidly excreted in the... 

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