Isolation from bacteria

The FDA first approved use of a polyether ionophore as a feed additive for catde ia 1975. Ionophores were first isolated from bacteria generally of the Streptomjces genus, but are produced commercially by bacterial fermentation (qv). Monensia [17090-79-8] and other ionophores are being fed to over 90% of feedlot cattle grown for beef (53) to enhance efficiency of gain improvements of 5—10% are common. Ionophores also are used as anticoccidial dmgs ia poultry production and have similar, but lesser, effects ia mminants (54). 

In contrast to vitamin K, there has been considerably more activity on fermentative approaches to vitamin (50). The biosynthetic pathway to vitamin K2 is analogous to that of vitamin except that poly(prenylpyrophosphates) are the reactive alkylating agent (51,52). Menaquinones of varying chain lengths from to have been isolated from bacteria. The most common forms are vitamin K2 35, (40) (45) significant amount of K2 20)... 

Knowledge of the coenzyme forms of vitamin Bi2 has increased steadily. The first coenzyme of Bi2 isolated from bacteria had similarities to pseudovitamin Bi2 it contained adenylic acid instead of 5,6-dimethyl-benzimidazole, but differed in lacking cyanide and having an extra molecule of adenine which was assumed to be bound to the cobalt atom by the coordination site, often occupied by cyanide (B24). This coenzyme, adenylcobamide, was completely inactive for Ochromonas malhamensis, but active for Escherichia coli 113-3. 

Rebeccamycin is an antitumor or antibiotic agent isolated from bacteria " and contains a maleimide indolocarbazole framework. The Trp units in this molecule are chlorinated at the C-7 position and a flavin-dependent halogenase was identified as the enzyme that carries out this chlorination (Scheme 10). " There are many other halogenating enzymes known in the literature and these enzymes are responsible for the syntheses of metabolites containing bromine, chlorine, and fluorine. ... 

There is only a small selection of nonprotein amino acids that contain carbonyl groups in the form of ketone, aldehyde, and carboxylic acid moieties, as part of the side chain. The examples given in Table 6 are components of nonribosomal peptides isolated from bacteria or fungi and siderophores from bacteria. The biosynthesis of these amino acids is not clear however, some of the amino acids with carboxylic acid side chains may be traced back to the L-a-amino acids aspartic acid and glutamic acid. 

These enzymes are isolated from bacteria, their natural source. There are many different restriction endonucleases isolated from a variety of bacteria that are now readily available commercially. In bacteria they act as part of a restriction/modification system that protects the bacteria from infection by DNA viruses. 

Figure 1.2 The restriction enzyme ECORI, illustrated here, is one of hundreds isolated from bacteria and used by biotechnologists to cut DNA molecules so that they can be joined with other DNA molecules. This allows scientists to insert a desired genetic sequence into a strand of DNA.

Streptokinase (isolated from bacteria) 1-4% Allergic reaction increased incidence of binding antibody with recent infection of streptococcns... 

S-Adenosylmethionine decarboxylase is the first enzyme in the biosynthetic pathway to spermidine (Chapter 24). Whether isolated from bacteria, yeast, animals, or other eukaryotes, this enzyme always contains a bound pyruvoyl group.273 274b Both the... 

The naturally occurring nucleoside/nucleotide antibiotics, which have been isolated from bacteria, fungi, blue-green algae, and marine sponges, have proven to be useful biochemical probes in eucaryotic, procaryotic, viral, fungal, and plant systems. Some excellent reviews on the nucleo-side/nncleotide antibiotics are available. 

Nitrate reductases have been isolated from bacteria, plants and fungi and always contain molybdenum. Two types may be distinguished (a) the assimilatory nitrate reductases which catalyze the reduction of nitrate to nitrite, which ultimately is reduced to ammonia and used by... 

Anhydrous hydrogen fluoride has been successfully applied in the structural analysis of polysaccharides to cleave glycosidic linkages since the 1980s. Recently, triflic acid has been found to be a more potent and more selective agent.774 In structural studies, for example, polysaccharides isolated from bacteria were stable toward... 

This reaction is applicable to various N-sulfonylated /f,y-unsaturated amides. The products are analogs of natural /1-lactams recently isolated from bacteria and known as monobactams. 

More than 10,000 new compounds have been isolated from bacteria, fungi, microalgae, seaweed, sponges, soft corals, opisthobranch mollusks, bryozoans, echinoderms, and ascidians. 

Proteins that are to be studied by NMR must be specially prepared. Natural proteins almost exclusively contain 12C and 14N, neither of which is an NMR-active isotope. For analysis, the protein must be enriched with 13C and 15N. Isotopically-enriched proteins can be isolated from bacteria that are grown in the presence of 13C-enriched glucose and 15NH4C1. The resulting proteins are then handed off to the NMR experts. 

The tetracyclines bind ribosomal proteins and inhibit bacterial protein synthesis. The first tetracycline was discovered in 1948. Tetracyclines are classified as polyketides, and all are either isolated from bacteria or derived from other tetracyclines. Common examples include tetracycline (A.30) and doxycycline (A.31) (Figure A.8). 

Like tetracyclines, macrolides are also polyketides that are isolated from bacteria and inhibit protein synthesis in certain bacteria. Erythromycin (A.32) is the original macrolide (Figure A.9). Clarithromycin (Biaxin, A.33) and azithromycin (Zithromax, A.34) are semisynthetic derivatives of erythromycin. 

Nomenclature Restriction enzymes are isolated from bacteria, where they play a role in protecting the host cell against virus infection. Over 100 restriction enzymes have now been isolated and have been named according to the bacterial species from which they were isolated. The first three letters of the enzyme name are the first letter of the genus name and the first two letters of the species name. Since each bacterium may contain several different restriction enzymes, a roman numeral is also used to identify each enzyme. EcoRI, for example, was the first enzyme isolated from Escherichia cgli. 

When isolated from bacteria, prokaryotic RNA polymerase has two forms The core enzyme and the holoenzyme. The core enzyme is a tetramer whose composition is given as 0C2PP (two alpha subunits, one beta subunit, and one beta-prime subunit). Core RNA polymerase is capable of faithfully copying DNA into RNA but does not initiate at the correct site in a gene. That is, it does not recognize the promoter specifically. Correct promoter recognition is the function of the holoenzyme form of RNA polymerase. 

The elucidation of the role of ferredoxin in metabolism has stimulated interest in other non-heme iron proteins (San Pietro 85)). The cellular function of most of these proteins is unknown, but they are believed to serve as electron carriers at various loci in metabolism. Because of their possible chemical similarities with ferredoxin, some of them will be mentioned in this section, particularly those isolated from bacteria. 

A compound, Ci2H32N5+C1 , newly isolated from bacteria, was only soluble in water. Both the H and 13C spectra, when acquired in D2O, showed three signals of equal intensity. What is the structure ... 

Table 18.2. A nonexhaustive list of marine iminium alkaloids isolated from bacteria, sponges or ascidia, together with their biological activity...

A 3-Ketosteroid isomerase (3-KSI). This enz)mie catalyses the allylic isomerization of the 5,6 double bond of A5-3-ketosteroids to the 4,5 position by stereospecific intramolecular transfer of a proton. The enz)mie has been isolated from bacteria, and especially the 3-KSIs from Comamoms testosteroni and Pseudomonas putida have been investigated (Smith et al, 1980). The gene coding for the 3-KSI of Pseudomonas putida biot) e B has been cloned and its nucleotide sequence determined (Kim et al, 1994). 

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