Glycosyltransferases

Building a specific glycosidic bond by hand is one of organic chemistry's slowest chores: several hydroxyl groups of similar reactivity, a protective-group scheme pages long, and a purification at the end of it. A glycosyltransferase does the same job in one step, in water, at room temperature, putting the sugar exactly where you asked — right hydroxyl, right anomer, every time. That regio- and stereospecificity is why these enzymes (EC 2.4) have become the default route to defined oligosaccharides, glycan standards and glycosylated natural products, from milligram scouting runs through gram-scale production.

Eata Marisource supplies recombinant glycosyltransferases developed from marine bacterial sources — organisms whose enzymes have already proved their usefulness under cold, salty, nutrient-poor conditions. Every lot ships with a stated unit definition, a donor-and-acceptor specificity note and an activity assay you can reproduce, so the enzyme you receive behaves the way the certificate says it will.

What a glycosyltransferase does, precisely

Leloir-type glycosyltransferases take an activated sugar — a nucleotide diphosphate or nucleotide monophosphate sugar — and condense it onto an acceptor alcohol, releasing the nucleotide by-product. Each enzyme is built for one linkage: a β-1,4-galactosyltransferase will not hand you a β-1,3, and an α-2,3-sialyltransferase stays out of the α-2,6 business. Structure-wise the enzymes fold into two broad architectures, the GT-A fold with its metal-dependent DXH motif and the metal-independent GT-B fold, and they proceed by either inverting or retaining mechanisms — a distinction that matters when you are planning multi-step cascades or trying to interpret why a donor analog refuses to turn over.

Because the donor is pre-activated, unprotected sugars go straight into the reaction. Yields approaching quantitative are routine on soluble acceptors; the usual villains are nucleotide by-product inhibition and the price of the donor itself, and both have engineering answers we discuss below.

The eight workhorse nucleotide-sugar donors

Nearly every oligosaccharide of practical interest can be assembled from a small donor set, all commercially available or generated in situ by paired biosynthesis enzymes.

Why marine enzymes earn their place

Seawater is a cold, salty, dilute culture medium, and the bacteria that thrive in it evolved carbohydrate machinery to match. A genomic survey of culturable bacteria from the South China Sea's Zhenbei Seamount found glycosyltransferase genes in more than a third of representative isolates, with GT2, GT4 and GT51 among the most widespread families — the ocean floor is, genomically speaking, a GT repository. Model marine Flavobacteriia such as Zobellia galactanivorans and Formosa agariphila carry dozens of polysaccharide-utilization loci stacked with CAZyme genes, and newly described marine Fulvivirga species turn out to encode dozens of glycosyltransferases alongside their degradative armory.

Characterized marine transfer enzymes show the practical payoffs. A glycolipid glycosyltransferase from the ocean's most abundant heterotroph, Candidatus Pelagibacter (SAR11), turned out to be a GT4-family, GT-B-fold retaining enzyme that accepts UDP-glucose, UDP-galactose or UDP-glucuronic acid against a diacylglycerol lipid acceptor — exactly the relaxed donor tolerance synthetic chemists look for. An α-cyclodextrin glucanotransferase from a Yellow Sea Bacillus strain operates optimally near pH 8.5 and 55°C and delivers α-cyclodextrin as the majority product. Cold-adapted transfer activities such as the laminarin-branching transglycosylase from the marine flavobacterium Muricauda lutaonensis show peak activity at 20°C with thermal stability to spare — useful when the acceptor is a heat-sensitive molecule.

Enzyme families we keep in stock

Our catalog concentrates on the transfer families that route most glycan synthesis work, with donor and linkage specificity stated for each entry.

From seawater isolate to shipped vial

Every enzyme we sell starts as a sequence. Candidate genes are pulled from marine bacterial genomes — the publicly documented ones and strains from our own collection — codon-optimized and cloned into expression hosts, then screened for soluble expression before any purification begins. Recombinant production matters for reproducibility: no wild-type extracts, no batch-to-batch surprises, and a His-tag or tag-free design chosen per enzyme so downstream coupling and immobilization stay open options.

Cloning and construct verification begin at the bench: amplifying and checking candidate glycosyltransferase genes before expression.

Purification follows standard chromatography with strict activity bookkeeping at every step, and concentrates are exchanged into the storage buffer under gentle vacuum rather than heat — a deliberate choice for enzymes whose active sites are temperature-sensitive.

Low-temperature vacuum concentration preserves labile transferase activity between purification and formulation.

Two classic bottlenecks, engineered out

Anyone who has run a glycosyltransferase cascade knows the two failure modes: the nucleotide by-product that poisons the enzyme mid-reaction, and a donor bill that dwarfs everything else. Both have mature fixes, and we build our application support around them.

• By-product control — a coupled phosphatase scavenges the released NDP as it forms, or a recycling network regenerates the donor from the nucleotide in situ; both routes keep conversion near-quantitative and cut enzyme loading.
• Donor economy — donor-synthesis enzymes (kinases, mutases, nucleotidylyltransferases, epimerases) can be paired with the transferase in one pot, feeding cheap sugar-1-phosphates in and avoiding stoichiometric donor purchases altogether.
• Reusability — immobilization on polyacrylamide-type supports lets the enzyme be recovered and re-run; several GT systems in the literature report retained activity across repeated cycles.

Characterization that travels with the vial

Enzyme units are a surprisingly slippery currency — some suppliers count nanomoles per minute and others micromoles, so identical numbers can hide a thousand-fold difference. We print the definition on the certificate, every time, and support it with two independent activity read-outs.

Binding thermodynamics between enzyme, donor and acceptor are measured directly by isothermal titration calorimetry.

Routine activity release testing runs as a coupled phosphate-detection assay in microplate format.

Formats, filling and the cold chain

Lyophilized powders in buffer salts are the default format — they survive ambient handling en route and reconstitute in a single pipetting step. Solutions in 50% glycerol are available for enzymes destined for automated workstations, and immobilized preparations on beaded supports are offered for flow chemistry and repeated-batch use. Filling and aliquoting happen in a laminar-flow enclosure so the sterility you expect on arrival is the sterility that was produced.

Aliquoting and vial filling take place in a laminar-flow enclosure to keep bioburden out of the final container.

Cold-chain shipping is standard: insulated shippers with pre-conditioned gel packs keep product within its storage band from our door to yours, and every carton carries a storage-temperature statement on the paperwork so receiving can verify conditions before signing.

Temperature-sensitive enzyme lots travel in insulated shippers with pre-conditioned gel packs.

Where these enzymes earn their keep

Custom expression and route development

If the linkage you need is not on the shelf, the conversation usually starts with three facts: the structure you want, the acceptor you already have, and the scale in your head. From there we can source a candidate enzyme from marine genomic data, express and purify it to specification, and develop the donor-recycling scheme that makes the route affordable at your volumes. The same service covers the sibling enzyme classes — glycosidases, sulfatases and carbohydrate esterases — so a complete polysaccharide build-and-breakdown toolkit can be sourced from one supplier.

For Research or Industrial Raw Materials, Not For Personal Medical Use!