Secondary accession number

The database identifier is the name of the database that contains the linked entry. The primary identifier (in most cases the accession number) is the entry s primary key, while the secondary identifier complements the information given by the first identifier. The currently linked databases are listed in Table II. 

Accession number ] [Gene sequence] Alignment Modelling Secondary structure Figure 14.3 Information about an enzyme (e g., leucine dehydrogenase, LeuDH) in the databases. 

Databases are electronic filing cabinets that serve as a convenient and efficient means of storing vast amounts of information. An important distinction exists between primary (archival) and secondary (curated) databases. The primary databases represent experimental results with some interpretation. Their record is the sequence as it was experimentally derived. The DNA, RNA, or protein sequences are the items to be computed on and worked with as the valuable components of the primary databases. The secondary databases contain the fruits of analyses of the sequences in the primary sources such as patterns, motifs, functional sites, and so on. Most biochemical and/or molecular biology databases in the public domains are flat-file databases. Each entry of a database is given a unique identifier (i.e., an entry name and/or accession number) so that it can be retrieved uniformly by the combination of the database name and the identifier. 

Each SWISS-PROT entry consists of general information about the entry (e.g., entry name and date, accession number), Name and origin of the protein (e.g., protein name, EC number and biological origin), References, Comments (e.g., catalytic activity, cofactor, subuit structure, subcellular location and family class, etc.), Cross-reference (EMBL, PIR, PDB, Pfam, ProSite, ProDom, ProtoMap, etc.), Keywords, Features (e.g., active site, binding site, modification, secondary structures, etc.), and Sequence information (amino acid sequence in Swiss-Prot format, Chapter 4). 

Figure 2.2 Crystal structure of CCL17 (PDB accession number 1NR4) [78]. The secondary structural units forming the conserved chemokine fold are shown.

Aliphatic hydrocarbons can be prepared by the reduction of the readily accessible ketones with amalgamated zinc and concentrated hydrochloric acid (Clemmensen method of reduction). This procedure is particularly valuable for the prep>aration of hydrocarbons wdth an odd number of carbon atoms where the Wurtz reaction cannot be applied with the higher hydrocarbons some secondary alcohol is produced, which must be removed by repeated distillation from sodium. 

To date, the most frequently used ligand for combinatorial approaches to catalyst development have been imine-type ligands. From a synthetic point of view this is logical, since imines are readily accessible from the reaction of aldehydes with primary or secondary amines. Since there are large numbers of aldehydes and amines that are commercially available the synthesis of a variety of imine ligands with different electronic and steric properties is easily achieved. Additionally, catalysts based on imine ligands are useful in a number of different catalytic processes. Libraries of imine ligands have been used in catalysts of the Strecker reaction, the aza-Diels-Alder reaction, diethylzinc addition, epoxidation, carbene insertions, and alkene polymerizations. 

In the case of stepwise processes, the cleavage of the primary radical intermediate (often an ion radical) may be viewed in a number of cases as an intramolecular dissociative electron transfer. An extension of the dissociative electron transfer theory gives access to the dynamics of the cleavage of a primary radical into a secondary radical and a charged or neutral leaving group. The theory applies to the reverse reaction (i.e., the coupling of a radical with a nucleophile), which is the key step of the vast family of... 

In the materials processing industry, size reduction or comminution is usually carried out in order to increase the surface area because, in most reactions involving solid particles, the rate of reactions is directly proportional to the area of contact with a second phase. Thus the rate of combustion of solid particles is proportional to the area presented to the gas, though a number of secondary factors may also be involved. For example, the free flow of gas may be impeded because of the higher resistance to flow of a bed of small particles. In leaching, not only is the rate of extraction increased by virtue of the increased area of contact between the solvent and the solid, but the distance the solvent has to penetrate into the particles in order to gain access to the more remote pockets of solute is also reduced. This factor is also important in the drying of porous solids, where reduction in size causes both an increase in area and a reduction in the distance... 

A similar mechanism has also been shown to occur in brain cells. For example, continuous exposure of /1-adrenoceptors on rat glioma cells in vitro results in a rapid reduction in the responsiveness of the receptors. This is followed by a secondary stage of desensitization, whereby the number of /1-receptors decreases. It seems likely that the receptors are not lost but move into the cell and are therefore no longer accessible to the transmitter. 

---