Publications

• Chitin synthetase 2, a presumptive participant in septum formation in Saccharomyces cerevisiae.

  Sburlati A., Cabib E.

  Strains containing a disrupted structural gene for chitin synthetase (chs1::URA3) are defective in chitin synthetase 1 (Chs1) activity but contain normal amounts of chitin (Bulawa, C.E., Slater, M., Cabib, E., Au-Young, J., Sburlati, A., Adair, L., and Robbins, P. W. (1986) Cell 46, 213-225). We h ... >> More

  Strains containing a disrupted structural gene for chitin synthetase (chs1::URA3) are defective in chitin synthetase 1 (Chs1) activity but contain normal amounts of chitin (Bulawa, C.E., Slater, M., Cabib, E., Au-Young, J., Sburlati, A., Adair, L., and Robbins, P. W. (1986) Cell 46, 213-225). We have now detected in such strains a new chitin synthetase activity (Chs2), at levels about 5% of those of Chs1 in wild-type cells. Thus, Chs2 is presumably the physiological agent for chitin deposition in strains with a disrupted CHS1 gene and probably also in wild-type strains. Chs1 and Chs2 share certain properties, such as stimulation by N-acetylglucosamine and by partial proteolysis. They differ sharply, however, in divalent cation specificity and in pH optimum. Chs2 also shows less sensitivity than Chs1 to inhibition by polyoxin D or sodium chloride, a property that was used to demonstrate the presence of Chs2 in wild-type extracts. As in the case of Chs1, most of the Chs2 activity was found to be associated with the plasma membranes. This finding, together with the apparent zymogenic nature of Chs2, is consistent with the hypothesis, previously put forward for Chs1, that localized deposition of chitin is attained by activation of the zymogen form at a specific time and place. Function and significance of the two chitin synthetases are discussed in connection with fungal morphogenesis and evolution. << Less

  J Biol Chem 261:15147-15152(1986) [PubMed] [EuropePMC]

• Improved assay and mechanism of the reaction catalyzed by the chitin synthase from Saccharomyces cerevisiae.

  Fahnrich M., Ahlers J.

  1. An improved filtration method is introduced to perform kinetic investigations on the chitin synthase reaction. This method is especially suited for the assay of a large number of samples necessary in enzyme kinetic studies. 2. From initial rate data the possibility could be excluded that the tw ... >> More

  1. An improved filtration method is introduced to perform kinetic investigations on the chitin synthase reaction. This method is especially suited for the assay of a large number of samples necessary in enzyme kinetic studies. 2. From initial rate data the possibility could be excluded that the two-substrate reactions occurs by a random or a ping-pong mechanism. 3. Investigations of product inhibition exclude a rapid random mechanism but favour an ordered mechanism with UDP-N-acetylglucosamine as the first substrate. 4. This result was confirmed by isotope exchange studies. << Less

  Eur J Biochem 121:113-118(1981) [PubMed] [EuropePMC]