Abstract
The autolysis of trypsin and α-chymotrypsin is accelerated in the presence of colloidal silica and glass surfaces. It is proposed that adsorption of the enzymes (favoured by electrostatic factors) results in a conformational change that renders the adsorbed enzyme more susceptible to proteolytic attack. Although the adsorbed enzymes are more susceptible to proteolysis, their activity towards low-molecular-weight substrates is not affected, indicating a relatively minor conformational change on adsorption. The rates of autolysis in solution (i.e. in `inert' vessels) are second-order for both trypsin and α -chymotrypsin, with rate constants of 13.0mol−1·dm3·s−1 for trypsin (in 50mm-NaCl at pH8.0 at 25°C) and 10.2mol−1·dm3·s−1 for α-chymotrypsin (in 0.1m-glycine at pH9.2 at 30°C). In glass vessels or in the presence of small areas of silica surface (as colloidal silica particles), the autolysis of both trypsin and α-chymotrypsin can show first-order kinetics. Under these conditions, saturation of the surface occurs and the fast surface proteolytic reaction controls the overall kinetic order. However, when greater areas of silica surface are present, saturation of the surface does not occur, and, since for a considerable portion of the adsorption isotherm the amount adsorbed is approximately proportional to the concentration in solution, second-order kinetics are again observed. A number of negatively charged macromolecules have been shown similarly to increase the rate of autolysis of trypsin: thus this effect, observed initially with glass and silica surfaces, is of more general occurrence when these enzymes adsorb on or interact with negatively charged surfaces and macromolecules. These observations explain the confusion in the literature with regard to the kinetics of autolysis of α-chymotrypsin, where first-order, second-order and intermediate kinetics have been reported. A further effect of glass surfaces and negatively charged macromolecules is to shift the pH–activity curve of trypsin to higher pH values, as a consequence of the effective decrease in pH in the `microenvironment' of the enzyme associated with the negatively charged surface or macromolecule.
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Selected References
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- BIER M., NORD F. F., TERMINIELLO L. On the mechanism of enzyme action. LXI. The self digestion of trypsin, calcium-trypsin and acetyltrypsin. Arch Biochem Biophys. 1956 Nov;65(1):120–131. doi: 10.1016/0003-9861(56)90182-5. [DOI] [PubMed] [Google Scholar]
- BUCK F. F., VITHAYATHIL A. J., BIER M., NORD F. F. On the mechanism of enzyme action. 73. Studies on trypsins from beef, sheep and pig pancreas. Arch Biochem Biophys. 1962 May;97:417–424. doi: 10.1016/0003-9861(62)90099-1. [DOI] [PubMed] [Google Scholar]
- Baines N. J., Baird J. B., Elmore D. T. The kinetics of hydrolysis of derivatives of arginine, homoarginine and ornithine by trypsin. Biochem J. 1964 Mar;90(3):470–476. doi: 10.1042/bj0900470. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bauer C. A., Pettersson G. Effect of boric acid on the catalytic activity of Streptomyces griseus protease 3. Eur J Biochem. 1974 Jun 15;45(2):473–477. doi: 10.1111/j.1432-1033.1974.tb03572.x. [DOI] [PubMed] [Google Scholar]
- CHERVENKA C. H. The differentiation of two forms of chymotrypsin by their rates of urea denaturation. J Biol Chem. 1962 Jul;237:2105–2108. [PubMed] [Google Scholar]
- CHERVENKA C. H. Ultraviolet spectral changes related to the enzymic activity of chymotrypsin. Biochim Biophys Acta. 1959 Jan;31(1):85–95. doi: 10.1016/0006-3002(59)90442-1. [DOI] [PubMed] [Google Scholar]
- Douzou P., Balny C. Cryoenzymology in mixed solvents without cosolvent effects on enzyme specific activity. Proc Natl Acad Sci U S A. 1977 Jun;74(6):2297–2300. doi: 10.1073/pnas.74.6.2297. [DOI] [PMC free article] [PubMed] [Google Scholar]
- ERLANGER B. F., COOPER A. G., BENDICH A. J. ON THE HETEROGENEITY OF THREE-TIMES-CRYSTALLIZED ALPHA-CHYMOTRYPSIN. Biochemistry. 1964 Dec;3:1880–1883. doi: 10.1021/bi00900a015. [DOI] [PubMed] [Google Scholar]
- FRASER D., POWELL R. E. The kinetics of trypsin digestion. J Biol Chem. 1950 Dec;187(2):803–820. [PubMed] [Google Scholar]
- Gabel D., Kasche V. Autolysis of beta-trypsin. Influence of calcium ions and heat. Acta Chem Scand. 1973;27(6):1971–1981. doi: 10.3891/acta.chem.scand.27-1971. [DOI] [PubMed] [Google Scholar]
- Gabel D., Kasche V. Cooperative transitions between active -and -trypsin conformations. Biochem Biophys Res Commun. 1972 Aug 21;48(4):1011–1018. doi: 10.1016/0006-291x(72)90709-7. [DOI] [PubMed] [Google Scholar]
- Ingles D. W., Knowles J. R. The alpha-chymotryptic ydrolysis of glycine esters. Biochem J. 1966 May;99(2):275–282. doi: 10.1042/bj0990275. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Johnson P., Whateley T. L. The effect of glass and silica surfaces on trypsin and -chymotrypsin kinetics. Biochim Biophys Acta. 1972 Jul 13;276(1):323–327. doi: 10.1016/0005-2744(72)90035-6. [DOI] [PubMed] [Google Scholar]
- Kumar S., Hein G. E. Concerning the mechanism of autolysis of alpha-chymotyrpsin. Biochemistry. 1970 Jan 20;9(2):291–297. doi: 10.1021/bi00804a015. [DOI] [PubMed] [Google Scholar]
- Mares-Guia M. Hydrophobic interactions in the trypsin active center. The sensitivity of the hydrophobic binding site to side chain modifications in competitive inhibitors of the amidinium type. Arch Biochem Biophys. 1968 Sep 20;127(1):317–322. doi: 10.1016/0003-9861(68)90232-4. [DOI] [PubMed] [Google Scholar]
- Maurel P., Douzou P. Catalytic implications of electrostatic potentials: the lytic activity of lysozymes as a model. J Mol Biol. 1976 Apr 5;102(2):253–264. doi: 10.1016/s0022-2836(76)80052-6. [DOI] [PubMed] [Google Scholar]
- McLaren A. D., Packer L. Some aspects of enzyme reactions in heterogeneous systems. Adv Enzymol Relat Areas Mol Biol. 1970;33:245–308. doi: 10.1002/9780470122785.ch5. [DOI] [PubMed] [Google Scholar]
- SCHWERT G. W., TAKENAKA Y. A spectrophotometric determination of trypsin and chymotrypsin. Biochim Biophys Acta. 1955 Apr;16(4):570–575. doi: 10.1016/0006-3002(55)90280-8. [DOI] [PubMed] [Google Scholar]
- Taylor R. P., Vatz J. B., Lumry R. Control of conformation of -chymotrypsin through chemical modification. Biochemistry. 1973 Jul 17;12(15):2933–2940. doi: 10.1021/bi00739a025. [DOI] [PubMed] [Google Scholar]
- WU F. C., LASKOWSKI M. The effect of calcium on chymotrypsins alpha and B. Biochim Biophys Acta. 1956 Jan;19(1):110–115. doi: 10.1016/0006-3002(56)90391-2. [DOI] [PubMed] [Google Scholar]
- YON J. Action du chlorure de sodium sur l'autolyse de la trypsine. Biochim Biophys Acta. 1959 Jan;31(1):75–85. doi: 10.1016/0006-3002(59)90441-x. [DOI] [PubMed] [Google Scholar]
