Enzymatic potato starch modification and structure-function analysis of six diverse GH77 4-alpha-glucanotransferases

Stefan Jarl Christensen, Michael Schmidt Madsen, Signe Schram Zinck, Christinne Hedberg, Ole Bandsholm Sørensen, Birte Svensson, Anne S. Meyer*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

53 Downloads (Pure)


4-α-glucanotransferase (E.C. mediated glucan transfer in starch provides opportunities for production of clean label starch ingredients with unique gelling properties. 4-α-glucanotransferases belong to the monospecific glycoside hydrolase family 77 (GH77). Here, pH-temperature optima, steady-state kinetics, potato starch modifying properties and structural folds are reported for six phylogenetically distinct GH77 members, representing four different domain architectures including a novel dual catalytic domain 4-α-glucanotransferase from Lactococcus lactis. Four of the enzymes exhibited starch modifying activity leading to a gradual decrease of the amylose content, elongation of amylopectin chains, and enabling formation of firm starch gels. Unexpectedly, these diverse enzymes catalyzed similar changes in chain length distributions. However, the amylose depletion and amylopectin elongation rates spanned more than two orders of magnitude between the enzyme showing very different specific activities. Tt4αGT from Thermus thermophilus had highest temperature optimum (73 °C) and superior potato starch modifying efficacy compared to the other five enzymes.
Original languageEnglish
JournalInternational Journal of Biological Macromolecules
Pages (from-to)105-114
Publication statusPublished - 2023


  • 4-α-glucanotransferase
  • Enzymatic potato starch modification
  • Chain length distribution analysis


Dive into the research topics of 'Enzymatic potato starch modification and structure-function analysis of six diverse GH77 4-alpha-glucanotransferases'. Together they form a unique fingerprint.

Cite this