[Posterior arthroscopic subtalar arthrodesis for symptomatic adult talocalcaneal coalition]

Objective: To investigate the functional outcomes of posterior arthroscopic subtalar arthrodesis (PASTA) for adult patients presenting with symptomatic talocalcaneal coalition. Methods: The study was a retrospective case-series research.The data of 17 adult patients (17 feet) with symptomatic talocalcaneal coalitions,treated with PASTA from March 2018 to February 2022 in Xuzhou Central Hospital were collected.This procedure involved 10 males and 7 females,aged (42.4±7.5) years(range:31 to 58 years).There were 9 cases on the right side and 7 cases on the left side.According to the Rozansky classification,there were 4 cases of type Ⅰ,7 cases of type Ⅱ, 3 cases of type Ⅲ,3 cases of type Ⅳ.The following items such as wound healing and bony union of the subtalar joint were observed.Clinical assessment was performed using pain visual analogue scale (VAS),American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scores and 36-item short form health survey (SF-36) scores.The paired t test was used for data comparison. Results: The follow-up time was (24.8±6.9) months(range:12 to 40 months).There were no complications such as wound infection,deep vein thrombosis,nonunion,or screw breakage.One patient with preoperative spasm,relieved after the second surgical procedure (peroneal brevis tendon lengthening).The union time of the subtalar joint was (8.8±2.2) weeks(range:6 to 12 weeks).At the final follow-up,the VAS decreased from (6.4±1.3) to (1.3±0.9)(t=14.114,P<0.01), the AOFAS ankle-hindfoot score increased from (49.0±8.1) to (90.0±5.1)(t=38.782,P<0.01),and the SF-36 score increased from (50.8±9.5) to (91.0±4.9)(t=20.468,P<0.01). Conclusion: PASTA for adult patients presenting with symptomatic talocalcaneal coalition offers advantages of minimal trauma,fast recovery,and few complications,which is an effective method.

Efficacy of acupuncture for the treatment of Parkinson's disease-related constipation (PDC): A randomized controlled trial

Objective

To evaluate the efficacy of acupuncture in treating Parkinson's disease-related constipation (PDC).

Materials and methods

This was a randomized, controlled trial in which patients, outcome assessors, and statisticians were all blinded. Seventy-eight eligible patients were randomly assigned to either the manual acupuncture (MA) or sham acupuncture (SA) groups and received 12 sessions of treatment over a 4-week period. Following treatment, patients were monitored until the eighth week. The primary outcome was the change in weekly complete spontaneous bowel movements (CSBMs) from baseline after treatment and follow-up. The Constipation Symptom and Efficacy Assessment Scale (CSEAS), the Patient-Assessment of Constipation Quality of Life questionnaire (PAC-QOL), and the Unified Parkinson's Disease Rating Scale (UPDRS) were used as secondary outcomes.

Results

In the intention-to-treat analysis, 78 patients with PDC were included, with 71 completing the 4-week intervention and 4-week follow-up. When compared to the SA group, weekly CSBMs were significantly increased after treatment with the MA group (P < 0.001). Weekly CSBMs in the MA group were 3.36 [standard deviation (SD) 1.44] at baseline and increased to 4.62 (SD, 1.84) after treatment (week 4). The SA group's weekly CSBMs were 3.10 (SD, 1.45) at baseline and 3.03 (SD, 1.25) after treatment, with no significant change from baseline. The effect on weekly CSBMs improvement in the MA group lasted through the follow-up period (P < 0.001).

Conclusion

Acupuncture was found to be effective and safe in treating PDC in this study, and the treatment effect lasted up to 4 weeks.

Clinical trial registration

http://www.chictr.org.cn/index.aspx, identifier ChiCTR2200059979.

Effect of electroacupuncture for Pisa syndrome in Parkinson’s disease: A case report

BACKGROUND

Pisa syndrome (PS) refers to marked lateral flexion of the trunk with a Cobb angle greater than 10°, which is typically mobile and can be resolved by lying down. PS is one of the most common postural deformities secondary to Parkinson’s disease (PD) and can aggravate scoliosis in the advanced stages of PD.

CASE SUMMARY

Here, we present the case of a 53-year-old woman who presented with lateral curvature for 6 mo. Full spine X-ray films in the correct position showed that the thoracolumbar spine was bent to the right without any rotation of the vertebrae. The patient was diagnosed with Pisa syndrome. After receiving a month’s treatment with electroacupuncture, the Cobb angle decreased from 18.14° to 13.41°.

CONCLUSION

This case demonstrates that electroacupuncture can effectively improve Pisa syndrome secondary to PD with few side effects and a low risk of recurrence. Additionally, early accurate diagnosis and timely intervention are meaningful for the prognosis of PS.

[Effect of Daoqi Tongjing needling method on intra-uterine residue after drug abortion from the perspectives of Hegu (LI 4) and Sanyinjiao (SP 6)]

The paper introduces professor ZHUANG Li-xing's clinical experience in treatment of intra-uterine residue and lochia after drug abortion. Professor ZHUANG believes that this disorder is related to "dysfunction of the thoroughfare vessel and the conception vessel, qi deficiency and blood stagnation, and retention of turbid qi in the uterus" in pathogenesis. The treating principle should focus on "regulating the functions of the thoroughfare vessel and the conception vessel, tonifying qi and eliminating stasis, as well as promoting qi movement". Besides Hegu (LI 4) and Sanyinjiao (SP 6), the acupoints are added from the conception vessel. The Daoqi Tongjing needling technique (the specific technique for directing qi and preserving essence) is exerted flexibly instead of traditional reinforcing and reducing technique of acupuncture to tonify qi and remove stasis.

[Arthroscopic treatment of acute closed noninsertional rupture of Achilles tendon]

Objective: To investigate the clinical efficacy of arthroscopic treatment of acute closed noninsertional rupture of Achilles tendon. Methods: The clinical and imaging data of 30 patients (30 feet) with acute closed noninsertional rupture of Achilles tendon who were treated with all-inside arthroscopic technique at the Department of Hand and Foot Microsurgery,Xuzhou Central Hospital from June 2018 to June 2020 were analyzed retrospectively. There were 26 males and 4 females,aged (38.3±8.5)years old(range:19 to 66 years). There were 22 cases on the right side and 8 cases on the left side. The duration from injury to surgery was (2.1±1.4) days (range:1 to 7 days).All patients were treated with all-inside arthroscopic technique.The function of the ankle and the foot was assessed using visual analogue scale (VAS),the American Orthopaedic Foot & Ankle Society (AOFAS) ankle hindfoot scale and the Achilles tendon total rupture score (ATRS). The Arner-Lindholm score system was used to evaluate the excellent and good rate of clinical effect. Paired sample t test or rank-sum test was used for data comparison. Results: The patients were followed up for (18.6±2.2)months(range:12 to 28 months).All the wounds healed at the first stage.No complication such as infection,sural nerve injury or re-rupture happened.Two patinets felt mild pain after a long time exercise, and were alleviated by microwave therapy and stretching the Achilles tendon consistently.Another patient was unable to do a sustained single stance heel raise,which was recovered after repeated function practice.At the last follow-up,the VAS (M(IQR)) decreased from 6(5) preoperatively to 0(1)(Z=6.512,P<0.01),the AOFAS ankle hindfoot scale improved from 60.6±8.3 preoperatively to 96.3±4.8(t=-29.774,P<0.01),and the ATRS improved from 61.7±7.8 preoperatively to 97.1±2.3 (t=-53.661,P<0.01).According to the Arner-Lindholm score system,27 cases were excellent,3 cases were good,and the excellent and good rate was 100%. Conclusions: The all-inside arthroscopic technique not only ensures the quality of tendon ananstomosis,but also avoids injury to the sural nerve.It has the advantages of small trauma,faster recovery and fewer complications.

Acupuncture for Parkinson's disease: From theory to practice

Advances in molecular biology and biochemistry have improved the treatment of Parkinson's disease (PD). There has been extensive evidence on the benefit of standard treatment (e.g., deep brain stimulation, levodopa, and dopamine agonists) and acupuncture for PD. This article aims to distill the similarities and differences in the treatment concepts between Chinese and Western medicine from the perspective of reinforcing the deficiency and purging the excess, summarize the latest evidence on the benefits of acupuncture for PD from theory to practice, and propose prospective treatment options for PD.

[Arthroscopy-assisted percutaneous reduction and screw fixation for displaced intra-articular calcaneal fractures]

Objective: To investigate the surgical technology and clinical efficacy of using the all-inside arthroscopic treatment of intra-articular displaced calcaneal fracture. Methods: A retrospective analysis was made of 46 patients (46 feet) with intra-articular displaced calcaneal fractures treated by modified all-inside arthroscopic from December 2015 to December 2017 in Xuzhou Central Hospital. Twenty-eight cases (28 feet) were male and 18 cases (18 feet) were female, aged from 19 to 60 years (mean (39±13) years). The time from injury to operation was 1 to 10 days (mean (4.5±2.2) days). The pre-operative visual analogue scale (VAS) of pain ranged from 4 to 8 points, mean (6.3±1.8) points. No other combined injuries were found in the affected feet in all patients. All patients were treated with anterolateral, lateral and posterolateral approaches of arthroscopically assisted reduction for calcaneal fractures, and fixed with hollow screw. Main outcome measures included the pain, foot appearance, and the scores of the American Orthopedic Foot & Ankle Society (AOFAS) Scale and the Maryland Scale. Paired t test was used when the data before and after the operation were compared. Results: All incisions healed in one stage without postoperative complications such as nerve, vessel and tendon injury. The mean follow-up period ranged from 12 to 36 months, mean (21±9) months. Postoperatively X-ray showed complete fracture healing time was 8 to 12 weeks, mean (10.4±2.3) weeks. At the last follow-up, the ankle and talocalcaneal joints movement and appearance were ideal, and no traumatic arthritis was found. The VAS score of talocalcaneal joint was 0. AOFAS score increased from 58±13 to 96±9 and Maryland score increased from 72±11 to 98±8 after the operation, the differences were all significant (t=15.958, 12.496, both P<0.05). Conclusion: The all-inside arthroscopic treatment of the intra-articular displaced calcaneal fracture is an effective and precise method, with accurately outcomes, precise reduction and minimally postoperative complications.

[Analysis of the effect of two medial portals for the all-inside endoscopic treatment of recalcitrant plantar fasciitis]

Objective: To examine the clinical effect of all-inside endoscopic treatment of recalcitrant plantar fasciitis through two medial portals. Methods: The recalcitrant plantar fasciitis data of 67 cases (79 feet) that underwent two medial portals all-inside endoscopic treatment at Department of Hand and Foot Microsurgery, Xuzhou Central Hospital from October 2016 to June 2018 were retrospectively analyzed.There were 24 males (30 feet) and 43 females (49 feet) aged 44.3 years old(range:24-76 years).The mean disease duration from the specialist doctor intervention to operation was (23.7±11.0) months (range: 12-60 months). All the patients were treated with the two medial portals all-inside endoscopic procedure when the 6 months conservative treatment had failed.The endoscopic procedure including debridement and partial plantar fasciotomy.The clinical results,including pain,activity,gait and foot health quality,were scored using visual analogue pain scale (VAS),American Orthopaedic Foot & Ankle Society Ankle Hindfoot Scale (AOFAS) and SF-36. Results: All the patients were followed up for (15.2±6.7) months (range: 12-24 months). All cases achieved primarily healing of the wound without postoperative complications of nerve,vessel and tendon.At the last follow-up,the VAS decreased from (5.3±2.0) preoperative to 0 prooperative (t=21.60, P=0.000), AOFAS increased from (72.6±9.4) to (97.3±4.6)(t=19.43,P=0.000),SF-36 increased from (93.6±8.4) to (119.1±7.3) (t=18.78, P=0.000), non-recurrent calcaneal spur, normal foot and ankle activity was recorded. Conclusion: The two medial portals all-inside endoscopic procedure is effective for the treatment of recalcitrant plantar fasciitis.

Improved production of transgenic Dioscorea zingiberensis (Dioscoreaceae) by Agrobacterium tumefaciens-mediated transformation

The establishment of high-efficiency Agrobacterium-mediated transformation techniques could improve the production of Dioscorea zingiberensis, a medicinal species with a high diosgenin content. We co-cultivated embryogenic calli induced from mature seeds with A. tumefaciens strain EHA105. A binary vector, pCAMBIA1381, which contains the gfp and hpt genes under the control of the ubiquitin promoter and the CaMV 35S promoter, respectively, was used for transformation. Pre-culture, basic medium, acetosyringone, and bacterial density were evaluated to establish the most efficient protocol. The optimal conditions consisted of MS medium without CaCl(2) for pre- and co-cultivation, three days for pre-culture, addition of 200 μM AS, and an OD(600) of 0.5. The transgenic plants grown under selection were confirmed by PCR analysis and Southern blot analysis. This protocol produced transgenic D. zingiberensis plants in seven months, with a transformation efficiency of 6%.

Suppression of PPN/MG61 attenuates Wnt/beta-catenin signaling pathway and induces apoptosis in human lung cancer

Wingless and int homologue (Wnt) family proteins have been shown to have important roles in the decision of cell fate and behavior at multiple stages during the development and tumorigenesis. One of the Drosophila segment polarity genes, porcupine (porc) gene, encodes an evolutionarily conserved endoplasmic reticulum membrane protein involving in the post-translational processing of the Wnt family proteins. Here, we report that human homologue of Drosophila porc gene, PPN/MG61, was abundantly expressed in human cancer cell lines, but not in normal cells. We also found that PPN/MG61 was overexpressed in primary lung cancer tissue samples, compared to their matched normal tissue samples. Furthermore, when we used small interfering RNA to knock down PPN/MG61 mRNA in lung cancer cells expressing the gene, we observed apoptosis induction, along with decreased activity of Wnt pathway in those lung cancer cells. These data suggest that PPN/MG61 may be a novel marker for human lung cancer and that post-translational modification of the Wnt signal molecules by PPN/MG61 may be important for the function of Wnt pathway in lung cancer.

Novel alpha-L-fucosidase inhibitors from the bark of Angylocalyx pynaertii (Leguminosae)

The extract of bark of Angylocalyx pynaertii (Leguminosae) was found to potently inhibit mammalian alpha-L-fucosidases. A thorough examination of the extract resulted in the discovery of 15 polyhydroxylated alkaloids, including the known alkaloids from seeds of this plant, 1,4-dideoxy-1,4-imino-D-arabinitol (DAB), 1-deoxymannojirimycin (DMJ) and 2,5-imino-1,2,5-trideoxy-D-mannitol (6-deoxy-DMDP). Among them, eight sugar-mimic alkaloids showed the potent inhibitory activity towards bovine epididymis alpha-L-fucosidase and their Ki values are as follows: 6-deoxy-DMDP (83 microM), 2,5-imino-1,2,5-trideoxy-L-glucitol (0.49 microM), 2,5-dideoxy-2,5-imino-D-fucitol (17 microM), 2,5-imino-1,2,5-trideoxy-D-altritol (3.7 microM), DMJ (4.7 microM), N-methyl-DMJ (30 microM), 6-O-alpha-L-rhamnopyranosyl-DMJ (Rha-DMJ, 0.06 microM), and beta-L-homofuconojirimycin (beta-HFJ, 0.0053 microM). We definitively deduced the structural requirements of inhibitors of alpha-L-fucosidase for the piperidine alkaloids (DMJ derivatives). The minimum structural feature of alpha-L-fucosidase inhibitors is the correct configuration of the three hydroxyl groups on the piperidine ring corresponding to C2, C3 and C4 of L-fucose. Furthermore, the addition of a methyl group in the correct configuration to the ring carbon atom corresponding to C5 of L-fucose generates extremely powerful inhibition of alpha-L-fucosidase. The replacement of the methyl group of beta-HFJ by a hydroxymethyl group reduced its inhibitory potential about 80-fold. This suggests that there may be a hydrophobic region in or around the active site. The existence or configuration of a substituent group on the ring carbon atom corresponding to the anomeric position of L-fucose does not appear to be important for the inhibition. Interestingly, Rha-DMJ was a 70-fold more potent inhibitor of alpha-L-fucosidase than DMJ. This implies that the lysosomal alpha-L-fucosidase may have subsites recognizing oligosaccharyl structures in natural substrates.

In vitro inhibition and intracellular enhancement of lysosomal alpha-galactosidase A activity in Fabry lymphoblasts by 1-deoxygalactonojirimycin and its derivatives

Fabry disease is a lysosomal storage disorder caused by deficient lysosomal alpha-galactosidase A (alpha-Gal A) activity. Deficiency of the enzyme activity results in progressive deposition of neutral glycosphingolipids with terminal alpha-galactosyl residue in vascular endothelial cells. We recently proposed a chemical chaperone therapy for this disease by administration of 1-deoxygalactonojirimycin, a potent inhibitor of the enzyme, at subinhibitory intracellular concentrations [Fan, J.-Q., Ishii, S., Asano, N. and Suzuki, Y. (1999) Nat. Med. 5, 112-115]. 1-Deoxygalactonojirimycin served as a specific chaperone for those mutant enzymes that failed to maintain their proper conformation to avoid excessive degradation. In order to establish a correlation between in vitro inhibitory activity and intracellular enhancement activity of the specific chemical chaperone, a series of 1-deoxygalactonojirimycin derivatives were tested for activity with both alpha-Gal A and Fabry lymphoblasts. 1-Deoxygalactonojirimycin was the most potent inhibitor of alpha-Gal A with an IC50 value of 0.04 microM. alpha-Galacto-homonojirimycin, alpha-allo-homonojirimycin and beta-1-C-butyl-deoxygalactonojirimycin were effective inhibitors with IC50 values of 0.21, 4.3 and 16 microM, respectively. N-Alkylation, deoxygenation at C-2 and epimerization at C-3 of 1-deoxygalactonojirimycin markedly lowered or abolished its inhibition toward alpha-Gal A. Inclusion of 1-deoxygalactonojirimycin, alpha-galacto-homonojirimycin, alpha-allo-homonojirimycin and beta-1-C-butyl-deoxygalactonojirimycin at 100 microM in culture medium of Fabry lymphoblasts increased the intracellular alpha-Gal A activity by 14-fold, 5.2-fold, 2.4-fold and 2.3-fold, respectively. Weaker inhibitors showed only a minimum enhancement effect. These results suggest that more potent inhibitors act as more effective specific chemical chaperones for the mutant enzyme, and the potent competitive inhibitors of alpha-Gal A are effective specific chemical chaperones for Fabry disease.

Role of Ser-65 in the activity of alpha-galactosidase A: characterization of a point mutation (S65T) detected in a patient with Fabry disease

Fabry disease is a genetic disorder caused by deficient activity of alpha-galactosidase A (alpha-Gal A). Recent gene analysis of a Fabry patient revealed a point mutation (S65T) resulting in a significant decrease of enzyme activity (Chen, C.-H., et al. (1998) Hum. Mutat. 11, 328-330). In order to evaluate the role of Ser-65 in the alpha-Gal A activity and the molecular mechanism of its deficient enzyme activity in mammalian cells, we prepared gene products of S65T, S65A, and E66D mutations of alpha-Gal A by using an expression system with baculovirus/insect cells and characterized the kinetic and physical properties of those purified enzymes. The Km values of mutant enzymes were 3.5 (S65T), 3.4 (S65A), and 2.3 mM (E66D), using 4-methylumbelliferyl alpha-D-galactoside as a substrate, and the Vmax values were 2.7 x 10(6) (S65T), 3.4 x 10(6) (S65A), and 2.5 x 10(6) units/mg (E66D), respectively, which were similar to those of the normal enzyme (Km, 2.3 mM; Vmax, 2.3 x 10(6) units/mg). The in vitro stability of mutant enzymes at neutral pH was significantly reduced (S65T, 4% of normal; S65A, 29%; E66D, 54%). The intracellular alpha-Gal A activities of S65T, S65A, and E66D in COS1 cells transfected with corresponding plasmid DNAs were markedly lower than the normal enzyme activity (9, 26, and 68% of normal, respectively). However, intracellular enzyme activities were enhanced to 34% (S65T), 44% (S65A), and 80% (E66D) of normal, respectively, by cultivation of the cells with 20 microM 1-deoxygalactonojirimycin (a potent inhibitor of alpha-Gal A) for 24 h. These results suggest that Ser-65 is responsible for the stability of alpha-Gal A but not for the enzyme function.

Accelerated transport and maturation of lysosomal alpha-galactosidase A in Fabry lymphoblasts by an enzyme inhibitor

Fabry disease is a disorder of glycosphingolipid metabolism caused by deficiency of lysosomal alpha-galactosidase A (alpha-Gal A), resulting in renal failure along with premature myocardial infarction and strokes. No effective treatment of this disorder is available at present. Studies of residual activities of mutant enzymes in many Fabry patients showed that some of them had kinetic properties similar to those for normal alpha-Gal A, but were significantly less stable, especially in conditions of neutral pH (refs. 3-5). The biosynthetic processing was delayed in cultured fibroblasts of a Fabry patient, and the mutant protein formed an aggregate in endoplasmic reticulum, indicating that the enzyme deficiency in some mutants was mainly caused by abortive exit from the endoplasmic reticulum, leading to excessive degradation of the enzyme. We report here that 1-deoxy-galactonojirimycin (DGJ), a potent competitive inhibitor of alpha-Gal A, effectively enhanced alpha-Gal A activity in Fabry lymphoblasts, when administrated at concentrations lower than that usually required for intracellular inhibition of the enzyme. DGJ seemed to accelerate transport and maturation of the mutant enzyme. Oral administration of DGJ to transgenic mice overexpressing a mutant alpha-Gal A substantially elevated the enzyme activity in some organs. We propose a new molecular therapeutic strategy for genetic metabolic diseases of administering competitive inhibitors as 'chemical chaperons' at sub-inhibitory intracellular concentrations.

Enzymatic synthesis of a neoglycoconjugate by transglycosylation with Arthrobacter endo-beta-N-acetylglucosaminidase: a substrate for colorimetric detection of endo-beta-N-acetylglucosaminidase activity

The transglycosylation activity of endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae was used for the enzymatic synthesis of a novel oligosaccharide, Man6GlcNAc-p-nitrophenyl-alpha-D-glucose (Man6GlcNAc-Glc-pNP). The reaction was efficiently induced in aqueous solution containing dimethyl sulfoxide. In the medium containing 20% (v/v) dimethyl sulfoxide with 0.1 M Glc-pNP as an acceptor, the transglycosylation attained yields of 75% by high-performance anion-exchange chromatography. The structure of Man6GlcNAc-Glc-pNP was confirmed by ion mass spectrometry and 400 MHz 1H NMR spectrometry. Various endo-beta-N-acetylglucosaminidases hydrolyzed this oligosaccharide and Man6GlcNAc and Glc-pNP were released from the oligosaccharide by endo-beta-N-acetylglucosaminidase digestion. We have established a new procedure for the colorimetric detection of endo-beta-N-acetylglucosaminidase activity using Man6Glc-NAc-Glc-pNP, which is simple as that for other exoglycosidase assays with pNP-glycosides as substrates.

Detailed studies on substrate structure requirements of glycoamidases A and F

Glycoamidases (peptide-N4-(N-acetyl-beta-glucosaminyl)asparagine amidase, EC 3.5.1.52; also known as peptide: N-glycanases (PNGases) release N-linked oligosaccharides from glycopeptides and/or glycoproteins by hydrolyzing the glycosylated beta-amide bond of the asparagine side chain. The most widely used glycoamidases are those from Flavobacterium meningosepticum (glycoamidase F or PNGase F) and almond emulsin (glycoamidase A or PNGase A). To study the substrate structure requirement of these enzymes systematically, we synthesized >30 glycopeptides containing cellobiose, lactose, GlcNAc, and di-N,N'-acetylchitobiose (CTB). The length of the peptide was varied from one to five amino acids, and glycosylamines were linked to either Asn or Gln located at different positions in the peptide, including NH2 and COOH termini. Neither enzyme could cleave cellobiose and lactose glycopeptides, indicating that the 2-acetamido group on the Asn-linked GlcNAc is important in the recognition by both glycoamidases A and F. GlcNAc peptides could be cleaved by both enzymes, albeit not as effectively as CTB glycopeptides. Neither enzyme requires the Asn-Xaa-(Ser/Thr) sequence (required for N-glycosylation) for activity. Glycoamidase A could even hydrolyze a Gln-bound CTB glycopeptide, whereas the action of glycoamidase F on this substrate is minimal. While glycoamidase A could act on CTB dipeptides, glycoamidase F preferred a tripeptide or longer. The Km and Vmax values of glycoamidase A for t-butoxycarbonyl-(CTB)-Asn-Ala-Ser-OMe were 2.1 mM and 0.66 micromol/min/mg, respectively. A natural glycodipeptide, Man9-GlcNAc2-Asn-Phe, was also completely hydrolyzed by glycoamidase A.

Differential N-glycan patterns of secreted and intracellular IgG produced in Trichoplusia ni cells

Structures of the N-linked oligosaccharide attached to the heavy chain of a heterologous murine IgG2a produced from Trichoplusia ni (TN-5B1-4, High Five) insect cells were characterized. Coexpression of the chaperone immunoglobulin heavy chain-binding protein (BiP) in the baculovirus-infected insect cells increased the soluble intracellular and secreted IgG level. This facilitated the detailed analysis of N-glycans from both intracellular and secreted IgG. Following purification of the immunoglobulins using Protein A-Sepharose, glycopeptides, prepared by trypsin-chymotrypsin digestion, were further digested with glycoamidase from sweet almond emulsin to obtain the oligosaccharide moieties. The resulting oligosaccharides were then reductively aminated with 2-aminopyridine and the structures identified by two-dimensional high performance liquid chromatography mapping (Tomiya, N., Awaya, J., Kurono, M., Endo, S., Arata, Y., and Takahashi, N. (1988) Anal. Biochem. 171, 73-90). The N-glycans obtained from the secreted IgG contain 35% complex type, some with terminal galactose residues at either alpha1, 3-Man or alpha1,6-Man branches of the Man3GlcNAc2 core. The remaining oligosaccharides detected in the secreted IgG were principally hybrid (30%) and paucimannosidic (35%) type N-glycans. Most (84%) of these secreted glycoforms contained fucose alpha1, 6-linked to the innermost GlcNAc residue and the presence of a potentially allergenic fucose alpha1,3-linked to the innermost GlcNAc residue was also detected. In contrast, the intracellular immunoglobulins included 50% high mannose-type N-glycans with lower levels of complex, hybrid, and paucimannosidic-type structures. Reverse phase one-dimensional high performance liquid chromatography analysis of the IgG N-glycans in the absence of heterologous BiP exhibited a similar distribution of intracellular and secreted glycoforms. These studies indicate that Trichoplusia ni TN-5B1-4 cells are capable of terminal galactosylation. However, the processing pathways in these cell lines appear to diverge from mammalian cells in the formation of paucimannosidic structures, in the presence of alpha1,3-fucose linkages, and in the absence of sialylation.

Transfer of Man9GlcNAc to L-fucose by endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae

We have reported that transglycosylation activity of endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae (endo-A) can be enhanced to near completion using GlcNAc as an acceptor in a medium containing 30% acetone (Fan J-Q, Takegawa K, Iwahara S, Kondo A, Kato I, Abeygunawardana C, Lee YC (1995) J Biol Chem 270: 17723-29). In this paper, we found that the endo-A can also transfer an oligosaccharide, Man9GlcNAc, to L-Fuc using Man9GlcNAc2Asn as donor substrate in a medium containing 35% acetone. The transglycosylation yield was greater than 25% when 0.2 M L-Fuc was used as acceptor. The transglycosylation produce was purified by high performance liquid chromatography on a graphitized carbon column and the presence of L-Fuc was confirmed by sugar composition analysis and electrospray mass spectrometry. Sequential exo-glycosidase digestion of pyridyl-2-aminated transglycosylation product, Man9GlcNAc-L-Fuc-PA, revealed that a beta-anomeric configuration linkage was formed between GlcNAc and L-Fuc. The GlcNAc was found to be 1,2-linked to L-Fuc by two methods: i) collision-induced decomposition on electrospray mass spectrometry after periodate oxidation, reduction and permethylation of Man9GlcNAc-L-Fuc; and ii) preparation of Man9GlcNAc-L-Fuc-PA, its periodate oxidation and reduction, followed by hydrolysis and HPLC analysis. Thus, the structure of the oligosaccharide synthesized by endo-A transglycosylation was determined to be Man9GlcNAc beta (1,2)-L-Fuc. Methyl-beta-L-fucopyranoside, L-Gal are also acceptors for the enzymic transglycosylation. However, transglycosylation failed when methyl alpha-L-fucopyranoside, D-Fuc and D-Gal were used. These results indicate that the endo-A requires not only 3-OH and 4-OH to be equatorial but also a 4C1-conformation or equivalent conformation of the acceptor to perform transglycosylation.

Purification of 2-aminopyridine derivatives of oligosaccharides and related compounds by cation-exchange chromatography

A simple method for efficient removal of a large excess of 2-aminopyridine from the reaction mixture of pyridylamination of carbohydrates and related compounds by cation-exchange chromatography is presented. The method is especially suitable for purification and separation of small-sized pyridylaminated-(PA-) derivatives and large-scale preparations. Separation of PA-derivatives from 2-aminopyridine was accomplished by a Dowex 50X8 column (NH+4-form) eluted with 20 mM ammonium acetate buffer (pH 8.5). The PA derivatives thus purified can be used for high-performance liquid chromatography analysis directly. The method requires only 10 min to purify a sample, in contrast to an hour or longer required by the gel filtration method. Unlike the existing methods for purification method. Unlike the existing methods for purification of PA-oligosaccharides, which are applicable only in the range of 0.05-100 nmol, the cation-exchange method allows processing of much larger quantities of PA-derivatives. For example, PA-L-glyceraldehyde (10 mumol) was successful purified by a Dowex 50X8 column (1.5 x 17 cm) eluted with 20 mM ammonium acetate buffer (pH 8.75) within 3 h.

Enhanced transglycosylation activity of Arthrobacter protophormiae endo-beta-N-acetylglucosaminidase in media containing organic solvents

The transglycosylation activity of endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae (endo-A) was enhanced by inclusion of organic solvents in the reaction mixture. In aqueous solution, the transglycosylation yield relative to starting substrate was 32% using Man9GlcNAc2Asn as donor and 0.5 M GlcNAc as acceptor. However, in the media containing 30% (v/v) acetone, dioxane, N,N-dimethylformamide, or dimethyl sulfoxide with 0.5 M GlcNAc as acceptor, the transglycosylation attained yields of 89, 13, 28, and 75%, respectively, as analyzed by high performance anion exchange chromatography. The enzyme was stable in media containing up to 30% acetone, 30% dimethyl sulfoxide, or 20% N,N-dimethylformamide at 37 degrees C for at least 30 min. The acceptor (GlcNAc) concentration must be greater than 0.2 M for efficient transglycosylation. Electrospray mass spectrometry analysis of the transglycosylation product obtained in 30% acetone with Man5GlcNAc2Asn as donor and methyl alpha-2-acetamido-2-deoxy-D-glucopyranoside as acceptor showed a mass ion of m/z 1249.4, consistent with the expected molecular weight. Analysis by 1H NMR of the product revealed that transglycosylation occurred at the C-4 of GlcNAc and the linkage was of the beta-configuration. In the acetone-containing medium, Glc, Man, 2-deoxy-Glc, and methyl alpha-D-GlcNAc can serve as a good acceptor as GlcNAc. Less favorable acceptors are xylose, fructose, 6-deoxy-Glc, and 3-O-methyl-D-glucose. On the other hand, GalNAc, Gal, allose, and 3-deoxy-Glc could not serve as acceptors of the enzyme transglycosylation.

Synthesis of neoglycoconjugates by transglycosylation with Arthrobacter protophormiae endo-beta-N-acetylglucosaminidase. Demonstration of a macro-cluster effect for mannose-binding proteins

The transglycosylation activity of endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae (endo-A) can be enhanced dramatically by inclusion of organic solvent in the reaction mixture (see accompanying article; Fan, J.-Q., Takegawa, K., Iwahara, S., Kondo, A., Kato, I., Abeygunawardana, C., and Lee, Y. C. (1995) J. Biol. Chem. 270, 17723-17729). This finding was extended to synthesis of important intermediates for preparation of neoglycoconjugates. When 0.2 M GlcNAc-O-(CH2)6NH2, GlcNAc-O-CH2CH = CH2, GlcNAc-O-(CH2)3-CH = CH2, GlcNAc-O-(CH2)3NHCOCH = CH2, GlcNAc-S-CH2CN, GlcNAc-S-(CH2)3CH3, or GlcNAc-S-CH2-CONHCH2CH(OMe)2 were used as acceptors in 30% acetone-containing media, the transglycosylation was accomplished with about 80% yield. The transglycosylation yields to benzyl beta-GlcNAc (67%), 4-methyl-umbelliferyl beta-GlcNAc (66%), p-nitrophenyl beta-GlcNAc (33%), and (GlcNAc-beta-S-CH2CH2CH2)2 (43%) were lower, because their poor solubilities allowed only 0.05 M or lower concentrations in the reaction mixture. A micromole-scale synthesis of Man9GlcNAc2-O-(CH2)3-NHCOCH = CH2 (Man9GlcNAc2-NAP) was accomplished with 90% yield, and the structure of the transglycosylation product was confirmed by 1H NMR. Man9GlcNAc2-NAP was co-polymerized with acrylamide. The ratio of sugar side chain to acrylamide in this glycopolymer was 1:44 and the molecular weight of glycopolymer was estimated to be between 1,500,000 and 2,000,000 by high performance gel filtration chromatography. The glycopolymer was shown to be a much more efficient inhibitor of binding by recombinant rat mannose binding protein-carbohydrate recognition domains (MBP-CRD) from serum (I50 = 3.5 microM Man9GlcNAc2-sugar chain) and liver (I50 = 74.5 nM) than soybean agglutinin.

High-performance liquid chromatography of glycopeptides and oligosaccharides on graphitized carbon columns

High-performance liquid chromatography of carbohydrate materials on graphitized carbon columns (GCC) has some advantages over other types of chromatography. Oligosaccharides and glycopeptides with few amino acids are barely retained on reversed-phase columns even under high salt or low pH conditions, but can be retained effectively on a graphitized carbon column. Moreover, elution of GCC requires concentrations of organic solvents lower than that required for normal-phase columns. The usefulness of graphitized carbon columns is exemplified by the following results: (i) Man9GlcNAc2 with only Asn or Asn-Phe (derived from soybean agglutinin) was not retained by a C18 reversed-phase column, but could be separated on a GCC with a gradient of 10-45% CH3CN in 30 min. (ii) Ribonuclease B glycopeptides obtained by Pronase digestion could be separated on GCC with a gradient of 10-30% CH3CN, but they were not retained on a C18 reversed-phase column even with water as eluent. (iii) Oligosaccharides released from ribonuclease B by endo-beta-N-acetylglucosaminidase were separated from each other and peptides on GCC with a linear gradient of 10 mM NH4OH to 10 mM NH4OH-12.5% CH3CN in 50 min at 70 degrees C. Silica-based columns do not allow such an alkaline eluent. (iv) Chito-oligosaccharides (DP 1-9) are well separated within 40 min on GCC with a gradient (10 mM NH4OH-10 mM NH4OH with 25% CH3CN) at 50 degrees C. Chito-oligosaccharides could not be separated by high-performance anion exchange columns such as Carbopac PA-1.

Release of T-antigen, a carcinoma marker from native human cells, by endo-alpha-N-acetylgalactosaminidase of Alcaligenes sp

The endo-alpha-N-acetylgalactosaminidase from Alcaligenes sp. could release T-antigen (Ga1 beta 1----3GalNAc), a carcinoma-associated marker from asialo glycophorin and human cells. The released T-antigen from human asialo erythrocytes was determined by thin layer chromatography and gas liquid chromatography. The released T-antigen from human gastric carcinoma cell Kato III was identified by high performance liquid chromatographies with a reverse-phase column and a size fractionation column. Released T-antigen could be analyzed quantitatively by a sensitive method including pyridylamino derivatization and following high performance liquid chromatography. This suggests that the enzyme is useful for detection and determination of T-antigen from cells.

Action of endo-alpha-N-acetylgalactosaminidase from Alcaligenes sp. on amino acid-O-glycans: comparison with the enzyme from Diplococcus pneumoniae

Endo-alpha-N-acetylgalactosaminidase from Alcaligenes sp. released the disaccharide, Gal beta 1----3GalNAc, from both dansylated serine-GalNAc-Gal and threonine-GalNAc-Gal, and showed higher activity on the former than the latter. The Km values were 0.17 mM and 1.43 mM with DNS-Ser-GalNAc-Gal and DNS-Thr-GalNAc-Gal, respectively. The optimum pHs were found to be 4.5-7.5 and 4.5-6.0 on DNS-Ser-GalNAc-Gal and DNS-Thr-GalNAc-Gal, respectively. On the contrary, the enzyme from Diplococcus pneumoniae had low activity to release the disaccharide from the amino acid-O-glycans. The possibility that the same O-glycoside but linked to different aglycon amino acids may play a different biological role in glycoproteins is discussed.