Degradation patterns, similarities

T ine structural studies on woody cell walls attacked by ectoenzymes of fungi in situ are numerous (cf. 1,2). In contrast, investigations on the selective degradation of cell walls by enzymes isolated from fungi are few. Jutte and Wardrop (3) attempted the use of crude commercial cellu-lase preparations to determine the degradation pattern of Valonia cellulose and beechwood fibers. Similar use of commercial preparations of enzymes was made by Reis and Roland (4) to evaluate the nature of diverse cell walls and to show the distribution of polysaccharides. An endo-/ -l,4-xylanase with specific xylanolytic activities was isolated from a commercial cellulase preparation using chromatographic methods and... 

Avicelases or Cellobiohydrolase C - - Mannanase. The action of mannanase on delignified sprucewood holocelluloses that were treated with avicelase 1, avicelase 2, or cellobiohydrolase C for 48 hr gave similar degradation patterns. The rate of total degradation increased rapidly when the mannanase was added the rate was most pronounced in the case of avicelase 1 (Figure 4). 

For example, if a sample is found to contain any specific Aroclor, measure the area or height ratio of largest to second largest peak in the sample extract and compare the same to that in the standard. The comparison of peak ratios, however, should not always be strictly followed, as it can lead to erroneous rejection. For example, because some of the same chlorobiphenyl components are common to most Aroclors, the presence of two or more Aroclors in the sample can alter the peak-ratio pattern. Similarly, the kinetics of oxidative or microbial degradation of chlorinated biphenyls can be different for each compound in the PCB mixture. 

If the degradation patterns of the test and control samples at the same elevated temperatures are not statistically different, it can be assumed that they will degrade similarly at the storage temperatures. The closer the elevated temperatures are to the storage temperatures, the more confident we can be in making this statement. The experimental protocols used are similar to the protocols used with the Arrhenius equation. Degradation patterns of a family of products at certain elevated temperatures can be modeled and used to check the behavior of a new product that belongs to the family. 

Ryles (1988) investigated the stability of xanthan and found that its stability followed a pattern similar to that of polyacrylamide in terms of temperature however, the mechanisms are quite different. Xanthan s stability was independent of divalent metal ion concentration, but apparently it was related to the conformational transition temperature. The degradation of xanthan was a func-... 

Neutral CEH has been purified 2000-fold from bovine adrenal cortex [46], and is very similar to the hormone-sensitive lipase of rat adipose tissue [44,47,48]. Both activities increase in response to ACTH via a cAMP-dependent protein kinase [42,44,47,49]. Both have an apparent molecular weight of 84000 as determined by SDS-polyacrylamide gel electrophoresis and show identical activities toward different substrates including CE and TG. Finally, both are inhibited by NaF, Hg, and diisopropylfluorophosphate, and show identical peptide proteolytic degradation patterns [44,47]. 

In the Fc of IgG [9,23] the two CH3 domains are paired in a pattern similar to that found for the CH1-CL interaction (Fig. 6). The two CH2 domains show no close interaction but have interposed between them two branched N-linked carbohydrate chains which make little contact between one another in human Fc [23] but more extensive contact in rabbit Fc [30]. In the pairing of the CH3 domains, approximately 1000 A2 of surface per domain is involved in the interaction. In the Ch2 case the carbohydrate provides a substitute for the domain-domain contact and helps to stabilise the CH2 domain. However, the CH2-carbohydrate contact area is only about half that of, for example, the CH3-CH3 contact so that one might expect a lower inherent stability for the CH2 domain. Indeed the CH2 domain is more sensitive to proteolytic degradation than the other domains of IgG [24], Domain stability has also been related to the apparent softness of parts of the CH2 domain most remote from the CH2-CH3 interface as indicated by large temperature factors or missing electron density in the crystal analysis of human Fc [23]. A corresponding softness has not, however, been found for rabbit Fc (Sutton B.J., personal communication). Tables 1 and 2 show a comparison of known CH3 and CH2 sequences. 

The metabolic degradation of monolinuron and linuron in rats proceeds, on the basis of metabolites identified in urine, according to a pattern similar to that of diuron. Demethoxylation is followed by demethylation and several ring-hydroxylating and conjugation reactions. The main metabolites are free and conjugated 3-(2-hydroxy 4-chlorophenyl)urea (Bohme and Ernst, 1965). 

Thus, several factors combine to produce the different growth behaviors. In layers, the age-dependent decline in the rate of turnover of the protein and the convergence of the rates of synthesis and degradation are similar to the growth pattern seen in many species and tissues. 

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