Biocatalysts f
731
Part F | 30.1
30. Biocatalysts from Aplysia: Sweet Spot
in Enzymatic Carbohydrate Synthesis
Antonio Trincone
Speaking in general terms, glycosylation is considered to be an important method for the structural
modification of compounds with useful biological activities. Glycosylation allows conversion of
lipophilic compounds into hydrophilic ones, thus
improving their pharmacokinetic properties or giving access to new drug delivery systems (prodrugs).
Examples include synthetic carbohydrate-based
polymers used as coating agents and as biomedical
materials, or novel dietary carbohydrates introduced as food additives. Finally, chromophoric
oligosaccharides are of widespread interest for
the kinetic analysis of hydrolytic activities and
to characterize the mode of action of particular
enzymes (i. e., exo or endoglycosidases). Hence
carbohydrate-based compounds have proved to
be a valuable tool in different fields of applicative interest, such as clinical, biological, and
food chemistry. Different enzymes acting on these
molecules are commercially available, but a greater
interest would entail a search for biocatalysts
with new catalytic characteristics. The marine
environment has been shown to be a very interesting source for new glycosyl hydrolases both
for hydrolytic and synthetic applications. Aplysia
is a genus of sea hares belonging to the family
Aplysiidae, containing different species of organ30.1 Biocatalysis, Glycosylation
and Marine Enzymes............................ 731
30.2 Biocatalytic Methodologies to Access
Glycosides and Oligosaccharides ........... 732
30.2.1 Enzymes ................................... 732
30.2.2 Natural and Engineered Methods
for Synthesis ............................. 734
30.3 The Marine Ecosystem as a Source
for New Glycoside Hydrolases ............... 734
30.4 Glycoside Hydrolases Present
in the Genus Aplysia ............................ 735
30.5 Other Enzymatic Activities of Interest
Present in Aplysia sp............................ 741
30.6 Conclusion........................................... 742
References................................................... 742
isms. Aplysia fasciata and Aplysia kurodai are two
examples; they are herbivorous animals and eat
a variety of red, green, or brown algae and have
been revealed to be potent producers of a library
of glycoside hydrolases applied in the synthesis
and hydrolysis of glycosidic bonds. In this chapter,
examples of applications of such enzymes will be
discussed.
30.1 Biocatalysis, Glycosylation and Marine Enzymes
In the field of biocatalysis the need for new biocatalysts is a current topic that involves a series of different
points. Particular attention must be paid to several characteristics of enzymes if they are to be used on an
industrial scale, and different key properties are recognized for this aspect. Broad substrate specificity, which
generally characterizes extracellular fungal enzymes
and is useful for the general application of a biocatalyst, may not be strictly requested in fields such as
the production of fine chemicals and pharmaceuticals
or the hydrolysis of specific linkages for analytical purposes, where very selective biocatalysts ensure fidelity
towards very specific linkages and good yields. Substrate specificity and affinity somehow play leader roles
among other catalytic characteristics. As an evolved
property the specificity of a biocatalyst is linked to the
731
Part F | 30.1
30. Biocatalysts from Aplysia: Sweet Spot
in Enzymatic Carbohydrate Synthesis
Antonio Trincone
Speaking in general terms, glycosylation is considered to be an important method for the structural
modification of compounds with useful biological activities. Glycosylation allows conversion of
lipophilic compounds into hydrophilic ones, thus
improving their pharmacokinetic properties or giving access to new drug delivery systems (prodrugs).
Examples include synthetic carbohydrate-based
polymers used as coating agents and as biomedical
materials, or novel dietary carbohydrates introduced as food additives. Finally, chromophoric
oligosaccharides are of widespread interest for
the kinetic analysis of hydrolytic activities and
to characterize the mode of action of particular
enzymes (i. e., exo or endoglycosidases). Hence
carbohydrate-based compounds have proved to
be a valuable tool in different fields of applicative interest, such as clinical, biological, and
food chemistry. Different enzymes acting on these
molecules are commercially available, but a greater
interest would entail a search for biocatalysts
with new catalytic characteristics. The marine
environment has been shown to be a very interesting source for new glycosyl hydrolases both
for hydrolytic and synthetic applications. Aplysia
is a genus of sea hares belonging to the family
Aplysiidae, containing different species of organ30.1 Biocatalysis, Glycosylation
and Marine Enzymes............................ 731
30.2 Biocatalytic Methodologies to Access
Glycosides and Oligosaccharides ........... 732
30.2.1 Enzymes ................................... 732
30.2.2 Natural and Engineered Methods
for Synthesis ............................. 734
30.3 The Marine Ecosystem as a Source
for New Glycoside Hydrolases ............... 734
30.4 Glycoside Hydrolases Present
in the Genus Aplysia ............................ 735
30.5 Other Enzymatic Activities of Interest
Present in Aplysia sp............................ 741
30.6 Conclusion........................................... 742
References................................................... 742
isms. Aplysia fasciata and Aplysia kurodai are two
examples; they are herbivorous animals and eat
a variety of red, green, or brown algae and have
been revealed to be potent producers of a library
of glycoside hydrolases applied in the synthesis
and hydrolysis of glycosidic bonds. In this chapter,
examples of applications of such enzymes will be
discussed.
30.1 Biocatalysis, Glycosylation and Marine Enzymes
In the field of biocatalysis the need for new biocatalysts is a current topic that involves a series of different
points. Particular attention must be paid to several characteristics of enzymes if they are to be used on an
industrial scale, and different key properties are recognized for this aspect. Broad substrate specificity, which
generally characterizes extracellular fungal enzymes
and is useful for the general application of a biocatalyst, may not be strictly requested in fields such as
the production of fine chemicals and pharmaceuticals
or the hydrolysis of specific linkages for analytical purposes, where very selective biocatalysts ensure fidelity
towards very specific linkages and good yields. Substrate specificity and affinity somehow play leader roles
among other catalytic characteristics. As an evolved
property the specificity of a biocatalyst is linked to the