Enzymatic characterization of human alpha1,3-fucosyltransferase Fuc-TVII synthesized in a B cell lymphoma cell line

Plasticity of Performance Curves Can Buffer Reaction Rates from Body Temperature Variation in Active Endotherms

Endotherms regulate their core body temperature by adjusting metabolic heat production and insulation. Endothermic body temperatures are therefore relatively stable compared to external temperatures. The thermal sensitivity of biochemical reaction rates is thought to have co-evolved with body temperature regulation so that optimal reaction rates occur at the regulated body temperature. However, recent data show that core body temperatures even of non-torpid endotherms fluctuate considerably. Additionally, peripheral temperatures can be considerably lower and more variable than core body temperatures. Here we discuss whether published data support the hypothesis that thermal performance curves of physiological reaction rates are plastic so that performance is maintained despite variable body temperatures within active (non-torpid) endotherms, and we explore mechanisms that confer plasticity. There is evidence that thermal performance curves in tissues that experience thermal fluctuations can be plastic, although this question remains relatively unexplored for endotherms. Mechanisms that alter thermal responses locally at the tissue level include transient potential receptor ion channels (TRPV and TRPM) and the AMP-activated protein kinase (AMPK) both of which can influence metabolism and energy expenditure. Additionally, the thermal sensitivity of processes that cause post-transcriptional RNA degradation can promote the relative expression of cold-responsive genes. Endotherms can respond to environmental fluctuations similarly to ectotherms, and thermal plasticity complements core body temperature regulation to increase whole-organism performance. Thermal plasticity is ancestral to endothermic thermoregulation, but it has not lost its selective advantage so that modern endotherms are a physiological composite of ancestral ectothermic and derived endothermic traits.

Hepatitis B virus X protein specially regulates the sialyl lewis a synthesis among glycosylation events for metastasis

Background

The metastasis of hematogenous cancer cells is associated with abnormal glycosylation such as sialyl lewis antigens. Although the hepatitis B virus X protein (HBx) plays important role in liver disease, the precise function of HBx on aberrant glycosylation for metastasis remains unclear.

Methods

The human hepatocellular carcinoma tissues, HBx transgenic mice and HBx-transfected cells were used to check the correlation of expressions between HBx and Sialyl lewis antigen for cancer metastasis. To investigate whether expression levels of glycosyltransferases induced in HBx-transfected cells are specifically associated with sialyl lewis A (SLA) synthesis, which enhances metastasis by interaction of liver cancer cells with endothelial cells, ShRNA and siRNAs targeting specific glycosyltransferases were used.

Results

HBx expression in liver cancer region of HCC is associated with the specific synthesis of SLA. Furthermore, the SLA was specifically induced both in liver tissues from HBx-transgenic mice and in in vitro HBx-transfected cells. HBx increased transcription levels and activities of α2-3 sialyltransferases (ST3Gal III), α1-3/4 fucosyltransferases III and VII (FUT III and VII) genes, which were specific for SLA synthesis, allowing dramatic cell-cell adhesion for metastatic potential. Interestingly, HBx specifically induced expression of N-acetylglucosamine-β1-3 galactosyltransferase V (β1-3GalT 5) gene associated with the initial synthesis of sialyl lewis A, but not β1-4GalT I. The β1-3GalT 5 shRNA suppressed SLA expression by HBx, blocking the adhesion of HBx-transfected cells to the endothelial cells. Moreover, β1-3GalT 5 silencing suppressed lung metastasis of HBx-transfected cells in in vivo lung metastasis system.

Conclusion

HBx targets the specific glycosyltransferases for the SLA synthesis and this process regulates hematogenous cancer cell adhesion to endothelial cells for cancer metastasis.

Electronic supplementary material

The online version of this article (doi:10.1186/1476-4598-13-222) contains supplementary material, which is available to authorized users.

Biochemical characterization of Helicobacter pylori α-1,4 fucosyltransferase: metal ion requirement, donor substrate specificity and organic solvent stability

The effect of metal ions on the activity, the donor substrate specificity, and the stability in organic solvents of Helicobacter pylori α-1,4 fucosyltransferase were studied. The recombinant enzyme was expressed as soluble form in E. coli strain AD494 and purified in a one step affinity chromatography. Its activity was highest in cacodylate buffer at pH 6.5 in the presence of 20 mM Mn2+ ions at 37°C. Mn2+ ions could be substituted by other metal ions. In all cases, Mn2+ ions proofed to be the most effective (Mn2+ > Co2+ > Ca2+ > Mg2+ > Cu2+ > Ni2+ > EDTA). The enzyme shows substrate specificity for Type I disaccharide (1) with a KM of 114 μM. In addition, the H. pylori α-1,4 fucosyltransferase efficiently transfers GDP-activated L-fucose derivatives to Galβ1-3GlcNAc-OR (1). Interestingly, the presence of organic solvents such as DMSO and methanol up to 20% in the reaction medium does not affect significantly the enzyme activity. However, at the same concentration of dioxane, activity is totally abolished.

Distantly related plant and nematode core α1,3-fucosyltransferases display similar trends in structure-function relationships

Here, we present a comparative structure-function study of a nematode and a plant core α1,3-fucosyltransferase based on deletion and point mutations of the coding regions of Caenorhabditis elegans FUT-1 and Arabidopsis thaliana FucTA (FUT11). In particular, our results reveal a novel "first cluster motif" shared by both core and Lewis-type α1,3-fucosyltransferases of the GT10 family. To evaluate the role of the conserved serine within this motif, this residue was replaced with alanine in FucTA (S218) and FUT-1 (S243). The S218A replacement completely abolished the enzyme activity of FucTA, while the S243A mutant of FUT-1 retained 20% of the "wild-type" activity. Based on the results of homology modeling of FucTA, other residues potentially involved in the donor substrate binding were examined, and mutations of N219 and R226 dramatically affected enzymatic activity. Finally, as both FucTA and FUT-1 were shown to be N-glycosylated, we examined the putative N-glycosylation sites. While alanine replacements at single potential N-glycosylation sites of FucTA resulted in a loss of up to 80% of the activity, a triple glycosylation site mutant still retained 5%, as compared to the control. In summary, our data indicate similar trends in structure-function relationships of distantly related enzymes which perform similar biochemical reactions and form the basis for future work aimed at understanding the structure of α1,3-fucosyltransferases in general.

Enzyme inhibitors from marine invertebrates

Marine invertebrates are rich sources of small molecules with unique chemical skeletons and potent bioactivities. Historically, such compounds were discovered mainly through the use of assays for phenotype-oriented activities, such as cytotoxicity or antimicrobial effects. More recently, target-oriented searches for bioactive substances, as exemplified by enzyme inhibitors, have become much more common, given a growing need for small-molecule inhibitors essential for studies of complex processes at the interface of chemistry and biology. In this review, selected enzyme inhibitors from marine invertebrates are presented.

Co-expression of two mammalian glycosyltransferases in the yeast cell wall allows synthesis of sLex

Interactions between selectins and their oligosaccharide-decorated counter-receptors play an important role in the initiation of leukocyte extravasation in inflammation. L-selectin ligands are O-glycosylated with sulphated sialyl Lewis X epitopes (sulpho-sLex). Synthetic sLex oligosaccharides have been shown to inhibit adhesion of lymphocytes to endothelium at sites of inflammation. Thus, they could be used to prevent undesirable inflammatory reactions such as rejection of organ transplants. In vitro synthesis of sLex glycans is dependent on the availability of recombinant glycosyltransferases. Here we expressed the catalytic domain of human alpha-1,3-fucosyltransferase VII in the yeasts Saccharomyces cerevisiae and Pichia pastoris. To promote proper folding and secretion competence of this catalytic domain in yeast, it was fused to the Hsp150 delta carrier, which is an N-terminal fragment of a secretory glycoprotein of S. cerevisiae. In both yeasts, the catalytic domain acquired an active conformation and the fusion protein was externalised, but remained mostly attached to the cell wall in a non-covalent fashion. Incubation of intact S. cerevisiae or P. pastoris cells with GDP-[14C]fucose and sialyl-alpha-2,3-N-acetyllactosamine resulted in synthesis of radioactive sLex, which diffused to the medium. Finally, we constructed an S. cerevisiae strain co-expressing the catalytic domains of alpha-2,3-sialyltransferase and alpha-1,3-fucosyltransferase VII, which were targeted to the cell wall. When these cells were provided with N-acetyllactosamine, CMP-sialic acid and GDP-[14C]fucose, radioactive sLex was produced to the medium. These data imply that yeast cells can provide a self-perpetuating source of fucosyltransferase activity immobilized in the cell wall, useful for the in vitro synthesis of sLex.

Enforced fucosylation of neonatal CD34+ cells generates selectin ligands that enhance the initial interactions with microvessels but not homing to bone marrow

Hematopoietic progenitor/stem cell homing to the bone marrow requires the concerted action of several adhesion molecules. Endothelial P- and E-selectins play an important role in this process, but their ligands on a large subset of neonate-derived human CD34+ cells are absent, leading to a reduced ability to interact with the bone marrow (BM) microvasculature. We report here that this deficiency results from reduced α1,3-fucosyltransferase (FucT) expression and activity in these CD34+ cells. Incubation of CD34+ cells with recombinant human FucTVI rapidly corrected the deficiency in nonbinding CD34+ cells and further increased the density of ligands for both P- and E-selectins on all cord blood–derived CD34+ cells. Intravital microscopy studies revealed that these FucTVI-treated CD34+ cells displayed a marked enhancement in their initial interactions with the BM microvasculature, but unexpectedly, homing into the BM was not improved by FucTVI treatment. These data indicate that, although exogenous FucT enzyme activity can rapidly modulate selectin binding avidity of cord blood CD34+ cells, further studies are needed to understand how to translate a positive effect on progenitor cell adhesion in bone marrow microvessels into one that significantly influences migration and lodgement into the parenchyma.

Highly sensitive cell-based assay system to monitor the sialyl Lewis X biosynthesis mediated by alpha1-3 fucosyltransferase-VII

The sialyl Lewis X (sLe(x)) determinant on leukocytes serves as a ligand for selectin family cell adhesion molecules, and selectin-carbohydrate interaction is considered to play an important role in the process of leukocyte extravasation during inflammation. Among several alpha1-3 fucosyltransferases (FucTs), FucT-VII plays a critical role in the biosynthesis of sLe(x)-epitopes. Therefore, small molecules specifically designed to inhibit the FucT-VII enzyme may have potential as anti-inflammatory agents. Here, we have developed a versatile cell-based assay system to monitor sLe(x) biosynthesis using the GeneSwitch System. This system is a mifepristone (MFP)-inducible mammalian expression system, and human transfectant T lymphoblasts expressed the mRNA of FucT-VII and the sLe(x)-epitopes on the cell surface in a time-dependent manner in the presence of MFP, with very low background transcription. Furthermore, when the transfectants were treated with the FucT-VII inhibitor panosialin, sLe(x) expression on the induced cells was inhibited dose dependently without alteration at the mRNA level of FucT-VII. These results suggest that the FucT-VII may be a major regulator of the biosynthesis of the sLe(x)-epitopes on T lymphoblasts, and this cell-based assay may be utilized for a screening system of FucT-VII inhibitors.

Relationship of sialyl-Lewis(x/a) underexpression and E-cadherin overexpression in the lymphovascular embolus of inflammatory breast carcinoma

Inflammatory breast carcinoma (IBC) is characterized by florid tumor emboli within lymphovascular spaces called lymphovascular invasion. These emboli have a unique microscopic appearance of compact clumps of tumor cells retracted away from the surrounding endothelial cell layer. Using a human SCID model of IBC (MARY-X), we, in previous studies, demonstrated that the tumor cell embolus (IBC spheroid) forms on the basis of an intact and overexpressed E-cadherin/alpha,beta-catenin axis that mediates tumor cell-tumor cell adhesion. In the present study we examine the mechanism behind the apparent lack of binding of the tumor embolus to the surrounding endothelium. We find that this lack of tumor cell binding is because of markedly decreased sialyl-Lewis(x/a) (sLe(x/a)) carbohydrate ligand-binding epitopes on its overexpressed MUC1 and other surface molecules that bind endothelial E-selectin. Decreased sLe(x/a) is because of decreased alpha3/4-fucosyltransferase activity in MARY-X. The decreased sLe(x/a) fail to confer electrostatic repulsions between tumor cells, which further contributes to the compactness of the MARY-X spheroid by allowing the E-cadherin homodimeric interactions to go unopposed. MARY-X spheroids were retrovirally transfected with FucT-III cDNA, significantly raising their levels of fucosyltransferase activity and surface sLe(x/a). In parallel experiments, enzymatic transfers with a milk alpha1,3-fucosyltransferase and an alpha2,3-sialyltransferase (ST3GalIV) were performed on the MARY-X spheroids and increased surface sLe(x/a). The addition of sLe(x/a) by either manipulation caused disadherence of the MARY-X spheroids and the disruption of the E-cadherin homodimers mediating cell adhesion. Our findings support the cooperative relationship of sLe(x/a) underexpression and E-cadherin overexpression in the genesis of the lymphovascular embolus of IBC.

Production of soluble human alpha3-fucosyltransferase (FucT VII) by membrane targeting and in vivo proteolysis

The rational design of fucosyltransferase (FucT VII) inhibitors as potential medication in the treatment of rheumatoid arthritis requires the three-dimensional structure of this member of the glycosyltransferase family. Structure determination by X-ray diffraction analysis needs purified, soluble enzyme protein. For this purpose we developed a novel method for the high-yield production of soluble FucT VII by in vivo proteolysis. To obtain a soluble form of FucT VII a mammalian expression construct was made encoding an N-terminal portion of FucT VI (amino acids 1-63) fused with the stem region and catalytic domain of FucT VII (amino acids 39-342). Chinese hamster ovary cells stably transfected with this construct produced FucT activity in the supernatant, which has the same catalytic properties as wild-type FucT VII. This soluble form of FucT VII can be obtained in high amounts (1 mg/L) and can be efficiently purified by GDP-hexanolamine affinity chromatography. In conclusion, it was demonstrated that the intrinsic properties of FucT VII could be transferred to secreted FucT VII constructs, which may open possibilities for production of soluble forms of other members of the glycosyltransferase family as well.

Identification of a missense mutation (G329A;Arg(110)--> GLN) in the human FUT7 gene

The human FUT7 gene codes for the alpha1,3-fucosyltransferase VII (Fuc-TVII), which is involved in the biosynthesis of the sialyl Lewis x (SLe(x)) epitope on human leukocytes. The FUT7 gene has so far been considered to be monomorphic. Neutrophils isolated from patients with ulcerative colitis were examined for apparent alterations in protein glycosylation patterns by Western blot analysis using monoclonal antibodies directed against SLe(x) and SLe(x)-related epitopes. One individual showed lower levels of SLe(x) expression and an elevated expression of CD65s compared to controls. The coding regions of the FUT7 gene from this individual were cloned, and a G329A point mutation (Arg(110) --> Gln) was found in one allele, whereas the other FUT7 allele was wild type. No Fuc-TVII enzyme activity was detected in COS-7 cells transiently transfected with the mutated FUT7 construct. The FUT7 Arg(110) is conserved in all previously cloned vertebrate alpha 1,3-fucosyltransferases. Polymerase chain reaction followed by restriction enzyme cleavage was used to screen 364 unselected Caucasians for the G329A mutation, and a frequency of < or =1% for this mutation was found (3 heterozygotes). Genetic characterization of the family members of one of the additional heterozygotes identified one individual carrying the G329A mutation in both FUT7 alleles. Peripheral blood neutrophils of this homozygously mutated individual showed a lowered expression of SLe(x) and an elevated expression of CD65s when analyzed by Western blot and flow cytometry. The homozygous individual was diagnosed with ulcer disease, non-insulin-dependent diabetes, osteoporosis, spondyloarthrosis, and Sjögren's syndrome but had no history of recurrent bacterial infections or leukocytosis.

Systematic synthesis of sulfated sialyl-alpha-(2 --> 3)-neolactotetraose derivatives and their acceptor specificity for an alpha-(1 --> 3)-fucosyltransferase (Fuc-TVII) involved in the biosynthesis of L-selectin ligand

Sulfated sialyl-alpha-(2 --> 3)-neolactotetraose (IV3NeuAcnLcOse4) derivatives at C-6 of GlcNAc (6-O-sulfo), terminal Gal (6'-O-sulfo), and both GlcNAc and Gal (6,6'-di-O-sulfo) residues have systematically been synthesized. (Methyl 5-acetamido-4,7,8,9- tetra-O-acetyl-3,5-dideoxy-D-glycero-alpha-D-galacto-2-nonulopyranosy lonate)-(2 --> 3)-2,4-di-O-benzoyl-6-O-levulinoyl-D-galactopyranosyl trichloroacetimidate was coupled with 2-(trimethylsilyl)ethyl (2-acetamido-2-deoxy- 3-O-benzyl-6-O-p-methoxyphenyl-beta-D-glucopyranosyl)-(1 --> 3)-(2,4,6-tri-O-benzyl-beta-D-galactopyranosyl)-(1 --> 4)-2,3,6-tri-O-benzyl-beta-D-glucopyranoside to give the suitably protected pentasaccharide which, upon selective removal of the p-methoxyphenyl and/or levulinoyl groups at C-6 of the GlcNAc and the terminal Gal residues, successive O-sulfation(s) and deprotection, afforded the desired three sulfated IV3NeuAcnLcOse4 derivatives. Acceptor specificity of the synthetic IV3NeuAcnLcOse4 probes for a human alpha-(1 --> 3)-fucosyltransferase (Fuc-TVII) was examined to study the biosynthetic pathway of L-selectin ligand. Only the 6-sulfated derivative at C-6 of GlcNAc was recognized by Fuc-TVII to give 6-O-sulfo sialyl LeX.

The cytoplasmic, transmembrane, and stem regions of glycosyltransferases specify their in vivo functional sublocalization and stability in the Golgi

We provide evidence for the presence of targeting signals in the cytoplasmic, transmembrane, and stem (CTS) regions of Golgi glycosyltransferases that mediate sorting of their intracellular catalytic activity into different functional subcompartmental areas of the Golgi. We have constructed chimeras of human alpha1, 3-fucosyltransferase VI (FT6) by replacement of its CTS region with those of late and early acting Golgi glycosyltransferases and have stably coexpressed these constructs in BHK-21 cells together with the secretory reporter glycoprotein human beta-trace protein. The sialyl Lewis X:Lewis X ratios detected in beta-trace protein indicate that the CTS regions of the early acting GlcNAc-transferases I (GnT-I) and III (GnT-III) specify backward targeting of the FT6 catalytic domain, whereas the CTS region of the late acting human alpha1,3-fucosyltransferase VII (FT7) causes forward targeting of the FT6 in vivo activity in the biosynthetic glycosylation pathway. The analysis of the in vivo functional activity of nine different CTS chimeras toward beta-trace protein allowed for a mapping of the CTS donor glycosyltransferases within the Golgi/trans-Golgi network: GnT-I < (ST6Gal I, ST3Gal III) < GnT-III < ST8Sia IV < GalT-I < (FT3, FT6) < ST3Gal IV < FT7. The sensitivity or resistance of the donor glycosyltransferases toward intracellular proteolysis is transferred to the chimeric enzymes together with their CTS regions. Apparently, there are at least three different signals contained in the CTS regions of glycosyltransferases mediating: first, their Golgi retention; second, their targeting to specific in vivo functional areas; and third, their susceptibility toward intracellular proteolysis as a tool for the regulation of the intracellular turnover.

Fucose in N-glycans: from plant to man

Fucosylated oligosaccharides occur throughout nature and many of them play a variety of roles in biology, especially in a number of recognition processes. As reviewed here, much of the recent emphasis in the study of the oligosaccharides in mammals has been on their potential medical importance, particularly in inflammation and cancer. Indeed, changes in fucosylation patterns due to different levels of expression of various fucosyltransferases can be used for diagnoses of some diseases and monitoring the success of therapies. In contrast, there are generally at present only limited data on fucosylation in non-mammalian organisms. Here, the state of current knowledge on the fucosylation abilities of plants, insects, snails, lower eukaryotes and prokaryotes will be summarised.

Octa- and nonaprenylhydroquinone sulfates, inhibitors of alpha1,3-fucosyltransferase VII, from an Australian marine sponge Sarcotragus sp

Alpha1,3-fucosyltransferase (Fuc TVII) is a key enzyme in the biosynthesis of selectin ligands. We have isolated two inhibitors of Fuc TVII from a marine sponge Sarcotragus sp. They were characterized as octa- and nonaprenylhydroquinone sulfates on the basis of spectral data. These compounds inhibited Fuc-TVII with IC50 values of 3.9 and 2.4 microg/mL, respectively.

Genetic engineering of recombinant glycoproteins and the glycosylation pathway in mammalian host cells

The analysis of many natural glycoproteins and their recombinant counterparts from mammalian hosts has revealed that the basic oligosaccharide structures and the site occupancy of glycosylated polypeptides are primarily dictated by the protein conformation. The equipment of many frequently used host cells (e.g. BHK-21 and CHO-cells) with glycosyltransferases, nucleotide-sugar synthases and transporters appears to be sufficient to guarantee complex-type glycosylation of recombinant proteins with a high degree of terminal alpha2-3 sialylation even under high expression conditions. Some human tissue-specific terminal carbohydrate motifs are not synthesized by these cells since they lack the proper sugar-transferring enzymes (e.g. alpha1-3/4 fucosyltransferases, alpha2-6 sialyltransferases). Glycosylation engineering of these hosts by stable transfection with genes encoding terminal human glycosyltransferases allows to obtain products with tailored (human tissue-specific) glycosylation in high yields. Using site-directed mutagenesis, unglycosylated polypeptides can be successfully converted in N- and/or O-glycoproteins by transferring glycosylation domains (consisting of 7-17 amino acids) from donor glycoproteins to different loop regions of acceptor proteins. The genetic engineering of glycoproteins and of host cell lines are considered to provide a versatile tool to obtain therapeutic glyco-products with novel/improved in-vivo properties, e.g. by introduction of specific tissue-targeting signals by a rational design of terminal glycosylation motifs.

In vivo specificity of human alpha1,3/4-fucosyltransferases III-VII in the biosynthesis of LewisX and Sialyl LewisX motifs on complex-type N-glycans. Coexpression studies from bhk-21 cells together with human beta-trace protein

Each of the five human alpha1,3/4-fucosyltransferases (FT3 to FT7) has been stably expressed in BHK-21 cells together with human beta-trace protein (beta-TP) as a secretory reporter glycoprotein. In order to study their in vivo properties for the transfer of peripheral Fuc onto N-linked complex-type glycans, detailed structural analysis was performed on the purified glycoprotein. All fucosyltransferases were found to peripherally fucosylate 19-52% of the diantennary beta-TP N-glycans, and all enzymes were capable of synthesizing the sialyl LewisX (sLex) motif. However, each enzyme produced its own characteristic ratio of sLex/Lex antennae as follows: FT7 (only sLex), FT3 (14:1), FT5 (3:1), FT6 (1.1:1), and FT4 (1:7). Fucose transfer onto beta-TP N-glycans was low in FT3 cells (11% of total antennae), whereas the values for FT7, FT5, FT4, and FT6 cells were 21, 25, 35, and 47%, respectively. FT3, FT4, FT5, and FT7 transfer preponderantly one Fuc per diantennary N-glycan. FT4 preferentially synthesizes di-Lex on asialo diantennary N-glycans and mono-Lex with monosialo chains. In contrast, FT6 forms mostly alpha1,3-difucosylated chains with no, one, or two NeuAc residues. FT3, FT4, and FT6 were proteolytically cleaved and released into the culture medium in significant amounts, whereas FT7 and FT5 were found to be largely resistant toward proteolysis. Studies on engineered soluble variants of FT6 indicate that these forms do not significantly contribute to the in vivo fucose transfer activity of the enzyme when expressed at activity levels comparable to those obtained for the wild-type Golgi form of FT6 in the recombinant host cells.

Panosialins, inhibitors of an alpha1,3-fucosyltransferase Fuc-TVII, suppress the expression of selectin ligands on U937 cells

Panosialins A and B were isolated as inhibitors of an alpha1,3-fucosyltransferase, Fuc-TVII, which is a key enzyme in the biosynthesis of selectin ligands, from culture broth of Streptomyces sp. Panosialins A and B inhibited the Fuc-TVII activity with IC50 values of 4.8 and 5.3 microg/ml, respectively. Panosialin A suppressed expression of selectin ligands on U937 cells, and inhibited the cell adhesion to immobilized E-selectin-immunoglobulin. Panosialins are the first reported Fuc-TVII inhibitors which can suppress the biosynthesis of selectin ligands and then inhibit selectin-mediated cell adhesion.

Detailed acceptor specificities of human alpha1,3-fucosyltransferases, Fuc-TVII and Fuc-TVI

To clarify the acceptor specificity of Fuc-TVII, its activity toward various analogs of a 2-(trimethylsilyl)ethyl alpha2,3-sialyl lacto-N-neotetraose, an acceptor for both Fuc-TVII and Fuc-TVI, was examined in comparison with that of Fuc-TVI. Fuc-TVII required three portions of alpha2,3-sialylated type-2 oligosaccharide structures (i.e., the hydroxyl group at C-4 of Gal, the hydroxyl group at C-3 of GlcNAc, and the carbonylamino group at C-2 of GlcNAc) for its acceptor recognition. Fuc-TVI required the carbonylamino group at C-2 of GlcNAc for its acceptor recognition. Fuc-TVII showed higher affinity toward two analogs, in which the hydroxyl group at C-6 of GlcNAc has been deoxygenated and the acetamide group of N-acetylneuraminic acid has been replaced with a glycolylamino group, respectively, than that toward the original compound. On the other hand, Fuc-TVI showed higher affinity toward an analog, in which the acetamide group of GlcNAc has been modified with a lauroylamino group, than that toward the original compound. Analysis involving mass spectrometry confirmed that both Fuc-TVII and Fuc-TVI could fucosylate these three analogs to yield sialyl Lewis x derivatives.