Abstract
Exopolygalacturonate lyase and pectinesterase from Clostridium multifermentans were assayed simultaneously in the same reaction mixture which contained a highly esterified pectin, polymethyl polygalacturonic acid methyl glycoside. Lyase is specific for unesterified galacturonide residues and cannot degrade this substrate in the absence of the esterase. The rate for esterase was twice the rate for lyase throughout the entire course of the combined reaction. Thus, the molar ratio of the two enzyme activities was the same since the product of the lyase is an unsaturated digalacturonic acid containing two free carboxyl groups. Since clostridial exopolygalacturonate lyase is known to degrade polygalacturonate in a linear manner beginning from the reducing ends of polygalacturonate chains, it was apparent that clostridial pectinesterase must hydrolyze methyl groups in highly esterified pectins with an action pattern similar to that of the lyase. Otherwise it would be impossible for the two enzyme rates to have corresponded on the basis of a 2:1 ratio.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Lee M., Macmillan J. D. Mode of action of pectic enzymes. 3. Site of initial action of tomato pectinesterase on highly esterified pectin. Biochemistry. 1970 Apr 28;9(9):1930–1934. doi: 10.1021/bi00811a011. [DOI] [PubMed] [Google Scholar]
- Lee M., Macmillan J. D. Mode of action of pectic enzymes. I. Purification and certain properties of tomato pectinesterase. Biochemistry. 1968 Nov;7(11):4005–4010. doi: 10.1021/bi00851a030. [DOI] [PubMed] [Google Scholar]
- MACMILLAN J. D., PHAFF H. J., VAUGHN R. H. THE PATTERN OF ACTION OF AN EXOPOLYGALACTURONIC ACID-TRANS-ELIMINASE FROM CLOSTRIDIUM MULTIFERMENTANS. Biochemistry. 1964 Apr;3:572–578. doi: 10.1021/bi00892a017. [DOI] [PubMed] [Google Scholar]
- MACMILLAN J. D., VAUGHN R. H. PURIFICATION AND PROPERTIES OF A POLYGALACTURONIC ACID-TRANS-ELIMINASE PRODUCED BY CLOSTRIDIUM MULTIFERMENTANS. Biochemistry. 1964 Apr;3:564–572. doi: 10.1021/bi00892a016. [DOI] [PubMed] [Google Scholar]
- Miller L., Macmillan J. D. Mode of action of pectic enzymes. II. Further purification of exopolygalacturonate lyase and pectinesterase from Clostridium multifermentans. J Bacteriol. 1970 Apr;102(1):72–78. doi: 10.1128/jb.102.1.72-78.1970. [DOI] [PMC free article] [PubMed] [Google Scholar]