Enzyme Properties and Nomenclature

Most Phase I oxidations are performed by cytochrome P-450. "Cytochrome," derived from Greek, literally means "colored substance in the cell." The color is derived from the properties of the outer electrons of the transition element iron. "P-450" denotes a reddish pigment with the unusual property of having its major optical absorption peak (Soret maximum) at about 450 nm, when it has been reduced and combined with carbon monoxide.330 Although the name "P-450" was intended to be temporary (until more was known about the substance), the terminology has persisted for 18 yr because of the increasing complexity of this enzyme system and because of the lack of agreement on new nomenclature. 

Thus, the EC numbers provide unique identifiers for enzyme functions, and give us useful keyword entries in database searches (http //www.chem.qmw.ac.uk/iubmb/ enzyme/). Enzyme nomenclature/common names and properties are also available at ENZYME (http //www.expasy.org/enzyme) and BRENDA (http //www.brenda.uni-koeln. de). IntEhz (http //www.ebi.ac.uk/intenzy) is the integrated enzyme database and enzyme nomenclature. Table 11.1 lists some enzyme resource sites providing general information. 

The chapters on organic chemistry (Chapters 1-6) were organized around the functional group concept. Each chapter dealt with a particular functional group or related groups. The nomenclature, properties, and uses of the compounds were discussed. The focus is different in this and the next four chapters (lipids, proteins, enzymes, and nucleic acids). Each of these chapters is devoted to a particular class of biomolecules—substances closely associated with life. Reactions and nomenclature receive much less emphasis more... 

Portal to databases of chemical suppliers lUBMB nomenclature for enzymes Nucleotide and protein sequences, protein structures, enzyme nomenclature and reactions Infrared, Raman, and mass spectra Portal to Infotherm, Acronyms, thermophysical properties See B.6... 

The full nomenclature can be browsed at http //www.chem.qmul.ac.uk/iubmb/enzyme/.) Like all proteins, enzymes are made as linear chains of amino acids that fold to produce a three-dimensional product. Each unique amino acid sequence produces a specific structure, which has unique properties. Enzymes can be denatured - that is, unfolded and inactivated - by heating or by chemical denamrants, which disrupt the three-dimensional structure of the protein denaturation may be reversible or irreversible. 

With the objective of studying the biocatalyst textural properties, N2 adsorption isotherms were obtained (Fig. 4), and according to the International Union Pure and Apphed Chemistry nomenclature, they are of type IV, which indicates that the solid contains a large proportion of mesopores (1.8-6 nm), and this facilitates the substrate access to the catalytic site of the immobilized enzyme. 

The discipline of biochemistry developed as chemists began to study the molecules of cells, tissues, and body fluids and physicians began to look for the molecular basis of various diseases. Today, the practice of medicine depends on understanding the roles and interactions of the enormous number of different chemicals enabling our bodies to function. The task is less overwhelming if one knows the properties, nomenclature and function of classes of compounds, such as carbohydrates and enzymes. The intent of this section is to review some of this information in a context relevant to medicine. Students enter medical school with different scientific backgrounds and some of the information in this section will, therefore, be familiar to many students. 

Metabolic pathways of microorganisms Portal to ProTherm (protein thermodynamics), ProNit (protein-nucleic acid interactions), biomolecule structures Crystal data and crystallization conditions for proteins, nucleic acids, and complexes Enzyme nomenclature and properties See B.5... 

Thermodynamic and thermophysical properties of ionic liquids and mixtures Miscibility and other properties of organic liquids Enzyme and nucleic acid nomenclature Portal to crystallographic databases See B.13 See B.13.b... 

European node of STN Easy Japanese node of STN Easy Enzyme nomenclature and related information Properties of environmental interest Nuclear energy levels, moments, and other properties... 

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