PROTEINS, ENZYMES, DNA and RNA

Acetoin dehydrogenase [from beef liver, acetoin NAD oxidoreductase] [9028-49-3] 76000 [EC 

Purify it via the acetone cake, then Ca-phosphate gel filtration (unabsorbed), lyophilised and then fractionated through a DEAE-22 cellulose coltrrrm. The Km for diacetyl is 40pM, and for NADH it is lOOpM in phosphate btrffer at pH 6.1. [Bttrgos Martin Biochim Biophys Acta 268 261 1972, 289 13 1972.] 

Purify it by Sephadex G-200 filtration and DEAE-cellttlose coltrrrm chromatography. The hexosamitridase A is further purified by DEAE-cellulose coluttm chromatography, followed by an ECTEOLA-cellulose coluttm, Sephadex-200 filtration, electrofocusing and Sephadex G-200 filtration. Hexosaminidase B is pttrified by a CM-cellulose coltunn, electrofocusing and Sephadex G-200 filtration. [Srivastava et al. J Biol Chem 249 2034 1974.] 

Acyl-coenzyme A Synthase [from beef Uver] [9013-18-7] Mr 57,000 [EC 6.2.1.2]. Purify the synthase by extraction with sucrose/HCOs buffer, protamine sulfate precipitation, (NH4)2S04 (66-65%) fiactination (pH 4.35) and a second (NH4)2S04 (35-60%) fractionation (pH 4.35). It has Km 0.15mM (F i 1.0) for octanoate and 0.41mM (Vrel 2.37) for heptanoate. The Km for ATP is 0.5mM, all at pH 9.0 in ethylene glycol buffer at 38°. [Jencks et al. J Biol Chem 204 453 1953, Methods Enzymol 5 467 19621] 

Acyl-coenzyme A Synthase (from yeast) [9012-31-1] Mr 151,000 [EC 6.2.1.1]. This enzyme has been purified by extraction into phosphate buffer pH 6.8-7.0 containing 2-mercaptoethanol and EDTA, protamine sulfate precipitation, polyethylene glycol fractionation. Alumina y gel filtration, concentration by (NH4)2S04 

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Figure 12.2. Advanced search for PDB file. From the PDB home page, select Advanced search field to open the PDB Search Fields form as shown. The advanced search enables the user to customize search fields including PDB identifier, author, chain types (protein, enzyme, DNA, and RNA, etc.), compound information, PDB header, experimental technique, text search, and result display options.

The early part of 20 century witnessed a sudden outburst of knowledge in chemical analysis, separation methods, electronic instrumentation for biological studies (X-ray diffraction, electron microscope, etc.) which ultimately resulted in understanding the structure and function of several key molecules involved in life processes such as proteins, enzymes, DNA and RNA. 

Riboflavin, riboflavin-5 -phosphate (Na salt, 2H2O) See entries in Miscellaneous Compounds and for ribonucleic acids see entry in Proteins, Enzymes, DNA and RNA in Chapter 6. 

Amino acids and peptides, Proteins Enzymes DNA and RNA, Carotenoids, Carbohydrates, Steroids, and Miscellaneous compounds which include Biochemical reagents. Cofactors, Coenzymes and Vitamins are collected in the separate respective sections in this chapter. 

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