R-Chymotrypsin

Fig. 2 Chromatographic comparison of protein elution profiles from PEZ and ZrP04 phases. Particles (4.5 pm) were packed in 50 mm X 4.6 mm i.d. eolumns. Mobile phase 30 min linear gradient from 50 to 500 mM potassium phosphate dibasic, pH 7.0 0.5 mL/min ambient temperature deteetion at 280 nm. Peaks 1—myoglobin, 2—lysozyme, 3— R-chymotrypsin, 4— ribonuclease A, 5—cytochrome c. (From Ref. [17].)...

The storage stability of proteases in ionic liquid media has also been studied [37, 59, 60]. Erbeldinger et al. [59] reported that the activity loss of thermolysin during preincubation proceeded much slower in [bmim "][PFg ] than in ethyl acetate. The storage stability of R-chymotrypsin in the ionic liquid [emim+][TfN2 ] was compared with that in water, 3 M sorbitol and 1-propanol. The enzyme s lifetime in [emim+][TfN2 ] at 30°C was 2, 6 and 96 times higher than that observed in 3 M sorbitol water and 1-propanol, respectively [37,60]. 

Trypsin cleaves after R. The other R is at the C-terminal, and carboxypeptidase will not cleave the C-terminal R. Chymotrypsin cleaves after Y. 

As a representative serine protease, R-chymotrypsin (ChT) provides an excellent enzyme model for studying the modulation of activity due to its well-defined structure and extensively characterized enzymatic properties [109]. As illustrated in Fig. 5.6a, the active pocket of ChT is surrounded by a ring of positively charged residues. Meanwhile, a number of hydrophobic hot spots are distributed on the... 

Fig. 5.6 (a) Molecular stiucture of R-chymotrypsin. (b) Chemical stiucture of amino-add-functionalized gold nanoparticles and SPNA-derived substrates, (c) Schematic representation of monolayer-controUed diffusion of the substrate into and the product away from the active pocket of nanoparticlebound ChT (Reprinted with permission from You et al. [110]. Copyright 2009 American Chemical Society)... 

Site of chymotrypsin catalyzed hydrolysis when R is an aromatic side chain... 

Porcine liver esterase (PLE) gives excellent enantioselectivity with both dimethyl 3-methylglutarate [19013-37-7] (lb) and malonate (2b) diester. It is apparent from Table 1 that the enzyme s selectivity strongly depends on the size of the alkyl group in the 2-position. The hydrolysis of ethyl derivative (2c) gives the S-enantiomer with 75% ee whereas the hydrolysis of heptyl derivative (2d) results in the R-monoester with 90% ee. Chymotrypsin [9004-07-3] (CT) does not discriminate glutarates that have small substituents in the 3-position well. However, when hydroxyl is replaced by the much bulkier benzyl derivative (Ic), enantioselectivity improves significantly. 

Matthews, B.W., Sigler, P.B., Henderson, R., Blow, D.M. Three-dimensional structure of tosyl-a-chymotrypsin. Nature 214 652-656, 1967. 

The actual reaction mechanism is very similar for the different members of the family, but the specificity toward the different side chain, R, differs most strikingly. For example, trypsin cleaves bonds only after positively charged Lys or Arg residues, while chymotrypsin cleaves bonds after large hydrophobic residues. The specificity of serine proteases is usually designated by labeling the residues relative to the peptide bond that is being cleaved, using the notation... 

Anand K, Palm GJ, Mesters JR, SiddeU SG, Ziebuhr J, HUgenfeld R (2002) Structure of coron-avirus main proteinase reveals combination of a chymotrypsin fold with an extra alpha-heUcal domain. EMBO J 21 3213-3224... 

For many solubilized enzymes the greatest catalytic activity and/or changes in conformation are found at R < 12, namely, when the competition for the water in the system between surfactant head groups and biopolymers is strong. This emphasizes the importance of the hydration water surrounding the biopolymer on its reactivity and conformation [13], It has been reported that enzymes incorporated in the aqueous polar core of the reversed micelles are protected against denaturation and that the distribution of some proteins, such as chymotrypsine, ribonuclease, and cytochrome c, is well described by a Poisson distribution. The protein state and reactivity were found markedly different from those observed in bulk aqueous solution [178,179],... 

The activity of a-chymotrypsin was found to be insensitive to the R value, i.e., from the size of the reversed micelles. This was taken as an indication that this enzyme is able to create its own micelles in the hydrocarbon rather than occupy empty ones and that the so-called exclusion effect, i.e., protein larger than the empty micelle cannot be solubilized, is incorrect [181,182],... 

CARVALHO M R, SGARBiERi V 0 (1998) Relative importance of phytohemagglutinin (lectin) and trypsin-chymotrypsin inhibitor on bean (Phaseolus vulgaris L) protein absorption and utilization by the rat. JNutr Sci Vitaminol (Tokyo). 44 685-96. 

Horton, H. R. Young, G. 2-Acetoxy-5-nitrobenzyl chloride. A reagent designed to introduce a reporter group near the active site of chymotrypsin. Biochem. Biophys. Acta. 1969, 94, 272-278. 

Figure 6 Separation of basic proteins on an untreated fused silica capillary with diaminopropane as buffer additive. Capillary 75 cm (55 cm to detector) x 50 p i.d. Buffer pHs are as noted on the figure with 30 to 60 mM DAP as an additive 200 to 240 V/cm peak identification 1 = lysozyme, 2 = cytochrome, 3 = ribonuclease, 4 = a-chymotrypsin 5 = trypsinogen, 6 = r-huIL-4. (From Bullock, J. A. and Yuan, L.-C., /. Microcol. Sep., 3, 241, 1991. With permission.)...

Campbell, R, and Gioannini, T.L. (1979) The use of benzophenone as a photoaffinity label. Labeling in p-benzoylphenylacetyl chymotrypsin at unit efficiency. Photochem. Photobiol. 29, 883. 

M. Prorok, A. Albeck, B. M. Foxman, R. H. Abeles, Chlo-roketone Hydrolysis by Chymotrypsin and N-Methylhistidyl-57-chymotrypsin Implications for the Mechanism of Chymotrypsin Inadivation by Chloro-ketones , Biochemistry. 1994,33, 9784-9790. 

Esters of higher diacids (e.g., dimethyl glutarates) have also proven quite informative. Thus, dimethyl 3-hydroxyglutarate (7.31) was hydrolyzed by PLE to the monoester of (S)-configuration (7.32), but the ee was low (ca. 20%) [55]. In contrast, a-chymotrypsin yielded the (R)-monoester with ee values of 60-70%, indicating large differences in the active sites of these... 

The enzymatic hydration of lactones is also documented, a variety of hydrolases having demonstrated activity. Very detailed kinetic studies have, for example, been published on the hydrolysis of oxazolones (7.78, R = H or Me, R = Me or aryl, R" = Me or Ph) catalyzed by a-chymotrypsin [163], These compounds are interesting from a chemical point of view, being enolic lac-... 

J. R. Grothusen, T. M. Brown, Stereoselectivity of Acetylcholinesterase, Arylester Hydrolase, and Chymotrypsin toward 4-Nitrophenyl Alkyl(phenyl)phosphinates , Pestic. Biochem. Physiol. 1986, 26, 100-106. 

Steitz TA, Henderson R, Blow DM. 1969. Structure of crystalline a-chymotrypsin. 3. Crystallographic studies of substartes and inhibitors bound to the active site of a-chymotrypsin. J Mol Biol 46 337-348. 

Sandanaraj BS, Vutukuri DR, Simard JM, Klaikherd A, Hong R, Rotello VM, Thayumanavan S. Noncovalent modification of chymotrypsin surface using an amphiphilic polymer scaffold implications in modulating protein function. J Am Chem Soc 2005 127 10693-10698. 

T.C. Liang, R.H. Abeles, Complex of alpha-chymotrypsin and N-acetyl-L-leucyl-L-phenylalanyl trifluoromethyl ketone Structural studies with NMR spectroscopy. Biochemistry 26 (1987) 7603-7608. 

K. Brady, A. Wei, D. Ringe, R.H. Abeles, Structure of chymotrypsin-trifluoromethyl ketone inhibitor complexes Comparison of slowly and rapidly equilibrating inhibitors. Biochemistry 29 (1990) 7600-7607. 

The strongest influence of configuration has been observed for Pi -substituted diastereomers of Z-Phe-(aTfm)Ala-Ala-NH2. The crystal structures of both dia-stereomers have been solved, which enables a better interpretation of this rather interesting effect. While the (S,S,S)-diastereomer has been shown to be almost as stable as the Aib-substituted peptide, the (S,R,S)-diastereomer was hydrolyzed very quickly within the same time range. Molecular modeling studies readily support the formation of hydrogen bonds as a possible explanation for this effect [18,54]. With the known crystal structure of the a-chymotrypsin/phenyl boronic... 

A. Tulinsky, R.A. Belvins, Structure of a tetrahedral transition state complex of alpha-chymotrypsin dimer at 1.8-A resolution, J. Biol. Chem. 262(16) (1987) 7737-7743. 

Blocher, M., Walde, R, and Dunn, I. J. (1999). Modeling of enzymatic reactions in vesicles the case of alpha-chymotrypsin. / Biotechnol Bioeng., 62, 36 3. 

Frenkel, K., Chrzan, K., Ryan, C. A., Wiesner, R., Troll, W. (1987). Chymotrypsin-speeifie protease inhibitors deerease H2O2 formation by aetivated human polymorphonuelear leukoeytes. Carcinogenesis, 8, 1207-1212. 

Der Curtius-Abbau geht von Malonsaure-monoestern aus, die iiber die Malonsaure-azid-ester zu racemischen a-Aminosaure-estern thermolysiert werden. Eine enantio-selektive Reaktion verwendet zur Verseifung der Malonsiiure-diester Chymotrypsin. Aus (R)-Benzyl-methylmalonsaure-monomethylester (98% ee) erhalt man z. B. (S)-y.-Methyl-phenylalanin1. 

J. A. Laszlo, D. L. Compton, Chymotrypsin-catalyzed transestrification in ionic liquids and ionic liquid/ supercritical carbon dioxide. In Ionic Liquids, R. D. Rogers, K. R. Seddon, Eds., ACS Symposium Series Vol. 

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