Maria Svedendahl Humble
About me
My research:
My research is focusing on enzyme engineering for improved biocatalytic applications. Different enzyme characteristics such as catalytic promiscuity, substrate enantioselectivity or structural stability are explored and targeted by combining molecular modeling and protein engineering.
Previous research:
PhD (KTH, 2003-2010): Exploring lipase catalytic promiscuity (conjugate addition and direct peroxidation reaction) and homology modeling of an omega-transaminase Arthrobacter citreus (Ac-TA) for improved and reversed enantioselectivity.
PostDoc (KTH, 2010-2011): Rational design by homology modeling of an omega-transaminase from Chromobacterium violaceum (Cv-TA) to improve and reverse the enzyme enantiospecificity and exploration of its crystal structure.
PostDoc (SU, 2011-2014): Development of an enzyme library screening assay in organic solvent. In the project, Candida antarctica lipase A (CalA) was applied as a model enzyme. In the library screen, an enzyme variant CalA (Y93L/L367I) showing an improved E-value from 3 to 100 (R) for 1-phenylethanol was found.
Current research:
Subtilisin Carlsberg (SC) is an interesting enzyme to study. This enzyme is known since 1947 and has a range of industrial applications. There are various crystal structures published and mutational data available for this enzyme. Besides its natural proteolytic activity, the enzyme can perform (S)-selective transacylation reactions in dry organic solvents. Normally, lipases are applied for (R)-selective transacylation reactions. An effective enzyme for (S)-selective transacylation reactions is demanded and SC is a promising candidate under investigation for this task.
In collaboration with Prof. Jan-Erling Bäckvall at the Department of Organic Chemistry at Stockholm University (SU) two different lipases (CalA and CalB) are explored for improved activities and enantiospecificities by using a combinatorial library approach. These two lipase libraries will be screened according to our previously published screening method in organic solvent with additional modification to suit the current model system.
In collaboration with Dr. Na Wang, lipase catalytic promiscuity and its lack of enantioselectivity is explored by molecular modeling and protein engineering methods.
Supervison of students:
Theresa Hol, Master thesis student (KTH) – Protein engineering of Subtilisin Carlsberg, 2014-2015
Anke Hering, Master thesis student (Ruhr University Bochum) – Widening the substrate scope of a novel lysine decarboxylase, 2014-2015
Robin Dorau, Master thesis student (Ruhr University Bochum) – Protein engineering of Subtilisin Carlsberg for improved performance in kinetic resolution of chiral alcohols, 2014-2015
Johanna Löfgren, co-supervision of PhD-student (Stockholm University, SU) - Protein engineering of lipases for organic synthesis applications, from 2015
Tamás Görbe, co-supervision of PhD-student (Stockholm University, SU) - Protein engineering of lipases for improved DKR-applications, from 2014
Shan Chen, co-supervision of PhD-student (KTH) - Engineering the stability of Cv-TA (organic solvent tolerance, substrate effects and thermostability), from 2014
Erica Rosander, co-supervision of Lic-student (KTH) - Development of a growth media for E. coli via enzymatic degradation of waste resources, from 2014