Translation changes

Some special features of proteins are elaborated by secondary transformations that are not part of the translation process. The A-formylmethionine initiator may be hydrolysed to methionine, or, as we have already indicated, the methionine unit may be removed altogether. Other post-translational changes to individual amino acids may be seen, e.g. the hydroxylation of proline to hydroxyproline (see Section 13.1) or the generation of disulfide bridges between cysteine residues (see Section 13.3). 

The isotropic part of the chemical shift tensor, piso, is invariant to any rotational and translational change of a given molecular unit... 

Many mechanisms have been found to contribute to desensitization. Some mechanisms function relatively slowly over the course of hours or days, and these typically involve transcriptional or translational changes in the receptor protein level, or its migration to the cell surface. Other mechanisms of desensitization occur quickly, within minutes. Rapid modulation of receptor function in desensitized cells may involve critical covalent modification of the receptor, especially by phosphorylation on specific amino acid residues, association of these receptors with other proteins, or changes in their subcellular location. 

Enzymatic modification of proteins applicable to foods is reviewed by Whitaker ( ). Described briefly are present uses of proteolytic enzymes for modifying proteins through partial hydrolysis. Major emphasis is placed on those enzymes which bring about aggregation of proteins, cross-link formation, and side chain modification through post-translational changes in the polypeptide chain. 

A wavelet is a general function, usually, but by no means exclusively, of time, g(t), which can be modified by translation (b) or dilation (expansion/contraction) (a). The function should add up to 0, and can be symmetric around its mid-point. A very simple example the first half of which has the value +1 and the second half —1. Consider a small spectrum eight datapoints in width. A very simple basic wavelet function consists of four —1 s followed by four —Is. This covers the entire spectrum and is said to be a wavelet of level 0. It is completely expanded and there is no room to translate this function as it covers the entire spectrum. The function can be halved in size (a = 2), to give a wavelet of level 1. This can now be translated (changing b), so there are two possible wavelets of level 1. The wavelets may be denoted by [n, m] where n is the level and m the translation. 

Translation Change void voids void, A. void, A. 

Translating changes in chemical potentials into changes in concentration is the next problem and it requires some scrutiny. We now have to split the dg s into their ionic components dg +d/i and dg = dg., + dg. and then... 

Table 1.2. Post-translational changes to proteins the modified coded amino acids present in proteins, including crosslinking amino acids (secondary amino acids)... 

Since iron is involved in many central nervous system processes that could affect infant behaviour and development, iron deficiency has adverse effects on brain development, both pre- and post-natal. In various epidemiological studies, it is reported that children with iron-deficiency anaemia have poorer performances on tests of some specific cognitive function. Animal experiments have identified some of the defects of reduced iron availability on brain function, which include post-translational changes (which result in a failure of iron incorporation into protein structures which are subsequently degraded), vulnerability of the developing hippocampus (with loss of the neuronal metabolic marker cytochrome c oxidase), and altered dendritic stmcture. Iron deficiency will also have a direct effect on myelin, including a decrease in myelin lipids and proteins, as well as neurotransmitter systems, since iron... 

Ronald Kuhr, an editor of this book and the head of the Department of Entomology at North Carolina State University told me, "I myself don t like to talk to reporters. It destroys your credibility as a scientist." Kuhr echoes a common complaint when he accuses journalists translations of what was said of being wrong. He believes, as do some other scientists, that while scientists tend to be very precise, journalists are not precise, and their translations change meanings. Before the translation, it is important to understand the reporter s involvement in the first place. 

Microsequencing provides clues about post-translational changes of the protein such as phosphorylation, sulfation, glycosylation, and the position of the disulfide bridges. Partial sequences can sometimes throw light on the relationships to other proteins. 

Oral administration of an aqueous extract of barley was reported to lower blood sugar in rabbits. Dose and duration of use were not specified in English language translations (Chang and But 1986 Chen and Chen 2004 Donard... 

The opioid peptides stem from a large precursor molecule in which several copies of the enkephalins are present, the ratio between Met-enkephalin and Leu-enkephalin being 6 1 [39]. The same precursor, pro-opiocortin, also contains a modified form of the enkephalin sequence in which the N-terminal tyrosine is present as the sulfate ester [40]. This kind of post-translational change has been discussed in connection with gastrin, cholecystokinin and caerulein (p. 165). The last mentioned peptide prompts us to recall dermorphin (p. 186), an opioid peptide found in the skin of an amphibian. 

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