Specific Degradation

This method will generally be applicable to simpler peptides. In the case of larger peptides, the complexity of the mixture will render fractionation difficult and a proportion of larger peptides will be required to work out an unambiguous result. 

In the choice of a suitable method of degradation three main factors are to be considered  

The reagent should cause a minimum of side reactions such as destruction of the constituent amino acids, or if such reactions do occur they should occur quantitatively to produce known products. 

The reagent should exhibit the desired specificity. Specific methods are required for the initial breakdown and several relatively non-specific methods are needed for the final elucidation of sequence. 

There should be a minimum of synthesis or rearrangement of peptide bonds under the influence of the reagent. 

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Litde is known about metaboHc inactivation of ( -endorphin and the dynorphins. NEP, and to a lesser extent APN, are only weaMy active against P-endorphin (183). Enzymes are known which degrade P-endorphin in vitro under nonphysiological conditions (202) or which inactivate P-endorphin by N-acetjlation (203). Alack of specific degradative enzymes for these peptides may account for their relatively long half-life in vivo though this has not been definitively estabUshed. 

Tsai listed and quantitatively discussed specific degradation mechanisms for environmental exposure [6-40] ... 

Multiple sclerosis The 150-kDa calpain specific degradation product of a-spectrin increases 50% in human MS plaques.44 Degradation of the 68-kDa neurofilament protein is inhibited by a synthetic calpain inhibitor45... 

The improvement of our knowledge on fruits cell wall has allowed us to describe new enzyme activities to specifically degrade these substrates to optimize the performance of industrial equipments and to allow to produce juices and concentrates with a higher quality in terms of oxidization, aromas level and stability. 

Exogenous enzymes are used to produce fruit juices more easily during different stages of the process i.e. maceration, liquefaction or juice depectinisation These biochemical tools induce specific degradations that the processor can integrate into his process line to manage and valorize the fruits transformation into juice. 

Cells of Acinetobacter sp. NCIB 9871 grown with cyclohexanol carried out enantiomeri-cally specific degradation of a racemic substituted norbomanone to a single ketone having >95% enantiomeric excess (Levitt et al. 1990). 

Bottiglieri M, C Keel (2006) Characterization of PhlG, a hydrolase that specifically degrades the antifungal compound diacetylphloroglucinol in the biocontrol agent Pseudomonas fluorescens CHAO. Appl Environ Microbiol 72 418-427. 

Quantity produced Transport specificity Degradation rate... 

There are various inhibitors within the coagulation system that counterregulate activation of the coagulation cascade. Among them, antithrombin III (AT-III) and protein C (PC) are the most important (SI). AT-III binds in the presence of heparin the activated factors F-IXa, F-Xa, and F-IIa (thrombin). PC is activated by a complex formed between thrombin and thrombomodulin, a surface protein of endothelial cells. Once activated, PC in the presence of protein S (PS) specifically degrades activated factors F-Va and F-VIIIa. PC decreases in the course of sepsis in relation to the severity of the condition (L15). Experimental studies have... 

The Environmental Fate Rate Constants refer to specific degradation processes rather than media. As far as possible the original numerical quantities are given and thus there is a variety of time units with some expressions being rate constants and others half-lives. The conversion is that the rate constant k is 0.693/t1/2 where t,A is the half-life. 

The Half-life in the Environment and Environmental Fate Rate Constants are medium-specific degradation reaction half-lives selected for use in Level II and Level III calculations. As discussed earlier, emphasis was based on the fastest and the most plausible degradation process for each of the environmental compartments considered. 

Weeds constitute one of the major problems in agriculture. They are an important constraint on yield in most crops across the world. These days, growers spend much money on weed control. About 6 million ton of herbicides was sold in the world in 2006 and herbicides are the most used pesticides they form approximately 38% of the total amount of pesticides (FAO 2006). Nowadays, an effort to tighten rules for authorization and application of pesticides, research and develop products that are target-specific, degrade quickly and do not accumulate in the food chain, exists in... 

V. Methylation Analysis Combined with Specific Degradation. 407... 

Specific degradation of the carbohydrate chain has been extensively discussed in a few articles (for reviews, see Refs. 5, 7, 8,35, and 58). In the following discussion, we shall briefly present some applications that have been valuable in the sequence study of glycoprotein and glycolipid saccharides. 

Product-specific formulations should be developed, taking account of specific degradation pathways to prevent chemical and physical changes, aggregation, adsorption and loss of biological activity, and to provide long-term stability on storage.18... 

Fourth, the salt concentration in cheese also influences the production of biogenic amines (Kebary et al., 1999 Joosten, 1988). Gouda cheese contains 3.5 mmol histamine per kg with a salt water ratio of 0.048, and 2.1 mmol histamine with a salt water ratio of 0.026 (Joosten, 1988). Each cheese has its own characteristic free amino acid and biogenic amine profiles, resulting from its specific degradation, interconversion, and synthesis (Polo et al., 1985). 

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