Tumour burden score combined with albumin-to-alkaline phosphatase ratio predicts prognosis in patients with intrahepatic cholangiocarcinoma.

Tumour morphology (tumour burden score (TBS)) and liver function (albumin-to-alkaline phosphatase ratio (AAPR)) have been shown to correlate with outcomes in intrahepatic cholangiocarcinoma (ICC). This study aimed to evaluate the combined predictive effect of TBS and AAPR on survival outcomes in ICC patients. We conducted a retrospective analysis using a multicentre database of ICC patients who underwent curative surgery from 2011 to 2018. The Kaplan-Meier method was employed to examine the relationship between a new index (combining TBS and AAPR) and long-term outcomes. The predictive efficacy of this index was compared to other conventional indicators. A total of 560 patients were included in the study. Based on TBS and AAPR stratification, patients were classified into three groups. Kaplan-Meier curves demonstrated that 124 patients with low TBS and high AAPR had the best overall survival (OS) and recurrence-free survival (RFS), while 170 patients with high TBS and low AAPR had the worst outcomes (log-rank p < 0.001). Multivariate analyses identified the combined index as an independent predictor of OS and RFS. Furthermore, the index showed superior accuracy in predicting OS and RFS compared to other conventional indicators. Collectively, this study demonstrated that the combination of liver function and tumour morphology provides a synergistic effect in evaluating the prognosis of ICC patients. The novel index combining TBS and AAPR effectively stratified postoperative survival outcomes in ICC patients undergoing curative resection.

Proteomic Landscape of Exosomes Reveals the Functional Contributions of CD151 in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer. Patients with TNBC have poor overall survival because of limited molecular therapeutic targets. Recently, exosomes have been recognized as key mediators in cancer progression, but the molecular components and function of TNBC-derived exosomes remain unknown. The main goal of this study was to reveal the proteomic landscape of serum exosomes derived from ten patients with TNBC and 17 healthy donors to identify potential therapeutic targets. Using a tandem mass tag-based quantitative proteomics approach, we characterized the proteomes of individual patient-derived serum exosomes, identified exosomal protein signatures specific to patients with TNBC, and filtered out differentially expressed proteins. Most importantly, we found that the tetraspanin CD151 expression levels in TNBC-derived serum exosomes were significantly higher than those exosomes from healthy subjects, and we validated our findings with samples from 16 additional donors. Furthermore, utilizing quantitative proteomics approach to reveal the proteomes of CD151-deleted exosomes and cells, we found that exosomal CD151 facilitated secretion of ribosomal proteins via exosomes while inhibiting exosome secretion of complement proteins. Moreover, we proved that CD151-deleted exosomes significantly decreased the migration and invasion of TNBC cells. This is the first comparative study of the proteomes of TNBC patient-derived and CD151-deleted exosomes. Our findings indicate that profiling of TNBC-derived exosomal proteins is a useful tool to extend our understanding of TNBC, and exosomal CD151 may be a potential therapeutic target for TNBC.

A putative effector of the rubber-tree powdery mildew fungus has elicitor activity that can trigger plant immunity.

MAIN CONCLUSION: A putative powdery mildew effector can elicit defense responses including reactive oxygen species and callose accumulations in model plants Nicotiana benthamiana and Arabidopsis thaliana and host plant Hevea brasiliensis. Powdery mildew fungi cause severe diseases in many agricultural plants, such as the mildew fungus Erysiphe quercicola infecting the rubber tree (Hevea brasiliensis), causing latex yield losses. However, effectors of E. quercicola were rarely functionally characterized. In this study, we identified a highly specific candidate-secreted effector protein, EqCSEP04187, from E. quercicola. This putative effector is expressed at the late stage but not the early stage during infection. The constitutive expression of EqCSEP04187 in model plants Nicotiana benthamiana and Arabidopsis thaliana elicited defense responses, as did transient expression of EqCSEP04187 in protoplasts of H. brasiliensis. Introducing EqCSEP04187 into another H. brasiliensis-associated fungal pathogen, Colletotrichum gloeosporioides, inhibited H. brasiliensis infection, and infection by E. quercicola was decreased in the A. thaliana eds1 mutant expressing EqCSEP04187. Further analysis suggests that these reductions in infection were the consequences of EqCSEP04187 eliciting defense responses. Our study suggests that this putative effector has elicitor activity that can improve plant resistance.

HbLFG1, a Rubber Tree (Hevea brasiliensis) Lifeguard Protein, Can Facilitate Powdery Mildew Infection by Suppressing Plant Immunity.

Powdery mildew causes substantial losses in crop and economic plant yields worldwide. Although powdery mildew infection of rubber trees (Hevea brasiliensis), caused by the biotrophic fungus Erysiphe quercicola, severely threatens natural rubber production, little is known about the mechanism by which E. quercicola adapts to H. brasiliensis to invade the host plant. In barley and Arabidopsis thaliana, lifeguard (LFG) proteins, which have topological similarity to BAX INHIBITOR-1, are involved in host plant susceptibility to powdery mildew infection. In this study, we characterized an H. brasiliensis LFG protein (HbLFG1) with a focus on its function in regulating defense against powdery mildew. HbLFG1 gene expression was found to be upregulated during E. quercicola infection. HbLFG1 showed conserved functions in cell death inhibition and membrane localization. Expression of HbLFG1 in Nicotiana benthamiana leaves and A. thaliana Col-0 was demonstrated to significantly suppress callose deposition induced by conserved pathogen-associated molecular patterns chitin and flg22. Furthermore, we found that overexpression of HbLFG1 in H. brasiliensis mesophyll protoplasts significantly suppressed the chitin-induced burst of reactive oxygen species. Although A. thaliana Col-0 and E. quercicola displayed an incompatible interaction, Col-0 transformants overexpressing HbLFG1 were shown to be susceptible to E. quercicola. Collectively, the findings of this study provide evidence that HbLFG1 acts as a negative regulator of plant immunity that facilitates E. quercicola infection in H. brasiliensis.

Meta-analysis of topical vancomycin powder for microbial profile in spinal surgical site infections.

OBJECTIVES: To systematically evaluate the impact of topical vancomycin powder for microbial profile in spinal surgical site infections. METHODS: All available literature regarding the topical use of vancomycin powder to prevent postoperative spinal infections was retrieved from the MEDLINE, EMBASE, and Cochrane databases starting from the creation date and up until September 30, 2018. RESULTS: A total of 21 studies involving 15,548 patients were reviewed. The combined odds ratio showed that topical use of vancomycin powder was effective for reducing the incidence of gram-positive bacterial infections in spinal surgical sites (OR 0.41, P < 0.00001) without affecting its efficacy in the prevention of polymicrobial infections (OR 0.30, P = 0.03). Additionally, it could significantly reduce the infection rate of methicillin-resistant staphylococcus (OR 0.34, P < 0.0001). However, topical vancomycin powder showed no advantage for preventing gram-negative bacterial infections (OR 0.94, P = 0.75). CONCLUSIONS: Topical administration of vancomycin powder may not increase the rates of gram-negative bacterial or polymicrobial infections in spinal surgical sites. On the contrary, it can significantly reduce the infection rates of gram-positive bacteria, methicillin-resistant staphylococcus (MRS) and microorganism. Of course, the topical vancomycin powder cannot change the rates of gram-negative bacterial infections, which may be related to the antimicrobial spectrum of vancomycin. Due to the limited number of articles included in this study, additional large-scale and high-quality studies are needed to provide more reliable clinical evidence.

Efficacy of hepatic arterial infusion chemotherapy in patients with primary liver cancer with portal vein tumor thrombosis: a comparative analysis of different perfusion chemotherapeutic regimens.

BACKGROUND: Portal vein tumor thrombosis (PVTT) commonly occurs in patients with primary liver cancer (PLC). Transarterial chemoembolization (TACE) is a treatment for patients with PLC and PVTT. Some studies have shown that combining TACE therapy with hepatic arterial infusion chemotherapy (HAIC) might improve the survival rate of PLC patients with PVTT. However, few studies have compared the different regimens of PLC with PVTT. We aimed to compare the differences between the oxaliplatin + raltetrexed regimen and FOLFOX regimen. METHODS: We divided the 248 patients into two groups. There were 60 patients in the oxaliplatin + ratitetrexed group and 74 patients in the FOLFOX group. The primary endpoints were OS and PFS. The secondary endpoints were ORR and adverse events. We used SPSS software, the Kaplan-Meier method, the t test, and the rank sum test to compare the differences between the two groups. RESULTS: The median OS was 10.82 months in the oxaliplatin + raltitrexed group and 8.67 months in the FOLFOX group. The median PFS time was greater in the oxaliplatin + raltitrexed group (10.0 months) than that in the FOLFOX group (7.1 months). The ORR was greater in the oxaliplatin + raltitrexed group than that in the FOLFOX group (18.3% vs. 13.5%; P = 0.445). The DCR in the oxaliplatin + raltitrexed group was higher than that in the FOLFOX group (70.0% vs. 64.8%; P = 0.529). However, in the subgroup analysis, the difference between them was more significant in the type II PVTT subgroup. The OS was 12.08 months in the oxaliplatin + raltitrexed group and 7.26 months in the FOLFOX group (P = 0.008). The PFS was 11.68 months in the oxaliplatin + raltitrexed group and 6.26 months in the FOLFOX group (P = 0.014). In the right branch of type II PVTT, the OS was 13.54 months in the oxaliplatin + raltitrexed group and 6.89 months in the FOLFOX group (P = 0.015), and the PFS was 13.35 months in the oxaliplatin + raltitrexed group and 6.27 months in the FOLFOX group (P = 0.030). The incidence of adverse reactions was similar between the two groups. CONCLUSIONS: Compared with the FOLFOX regimen, the oxaliplatin + raltitrexed chemoembolization regimen had longer OS, PFS time and ORR and DCR and it was safe and tolerable.

Exosome-shuttled miR-150-5p from LPS-preconditioned mesenchymal stem cells down-regulate PI3K/Akt/mTOR pathway via Irs1 to enhance M2 macrophage polarization and confer protection against sepsis.

Rationale: Sepsis is a life-threatening organ dysfunction and lack of effective measures in the current. Exosomes from mesenchymal stem cells (MSCs) reported to alleviate inflammation during sepsis, and the preconditioning of MSCs could enhance their paracrine potential. Therefore, this study investigated whether exosomes secreted by lipopolysaccharide (LPS)-pretreated MSCs exert superior antiseptic effects, and explored the underlying molecular mechanisms. Methods: Exosomes were isolated and characterized from the supernatants of MSCs. The therapeutic efficacy of normal exosomes (Exo) and LPS-pretreated exosomes (LPS-Exo) were evaluated in terms of survival rates, inflammatory response, and organ damage in an LPS-induced sepsis model. Macrophages were stimulated with LPS and treated with Exo or LPS-Exo to confirm the results of the in vivo studies, and to explain the potential mechanisms. Results: LPS-Exo were shown to inhibit aberrant pro-inflammatory cytokines, prevent organ damages, and improve survival rates of the septic mice to a greater extent than Exo. In vitro, LPS-Exo significantly promoted the M2 polarization of macrophages exposed to inflammation. miRNA sequencing and qRT-PCR analysis identified the remarkable expression of miR-150-5p in LPS-Exo compared to that in Exo, and exosomal miR-150-5p was transferred into recipient macrophages and mediated macrophage polarization. Further investigation demonstrated that miR-150-5p targets Irs1 in recipient macrophages and subsequently modulates macrophage plasticity by down-regulating the PI3K/Akt/mTOR pathway. Conclusion: The current findings highly suggest that exosomes derived from LPS pre-conditioned MSCs represent a promising cell-free therapeutic method and highlight miR-150-5p as a novel molecular target for regulating immune hyperactivation during sepsis.

Bone-to-Bone Ligament Preserving Laminoplasty with Ultrasonic Osteotome Assistance for Intraspinal Tumors: A Technical Note and Clinical Follow-Up.

OBJECTIVE: Laminectomy has been widely used for intraspinal tumor resection. However, the tilted spinous process and narrow lateral laminae of the thoracic spine along with the hypertrophic ligamentum flavum of the lumbar spine pose certain problems for the laminae removal of the traditional laminectomy. We improved the laminectomy method with ultrasonic osteotome to treat thoracolumbar tumors and assessed its safety and superiority. METHODS: A retrospective analysis was performed in 86 patients with thoracolumbar (T4-L5) spinal tumors treated by resection, including 44 with the lamina removed using the traditional method and 42 with the lamina removed using the bone-to-bone ligament preserving (BLP) laminoplasty, which preserves the posterior ligament complex. Age, sex, and tumor size, location, and depth were compared between the two groups. The length of incision and bone window, time to remove the vertebral lamina, and epidural effusion volume were recorded at 2 weeks after surgery in the two groups. Postoperative reexamination by magnetic resonance imaging (MRI) at 2 weeks and 3 months after surgery was compared with preoperative MRI to assess the change in vertebral lamina displacement. RESULTS: There were no statistical differences in age, sex, and tumor size, depth, or location between the two groups. The BLP laminectomy did not increase the risk of dural, spinal cord, or nerve injuries. The difference between the incision and tumor length, as well as the difference between the bone window and tumor length in the BLP laminectomy group, were smaller than those in the traditional laminectomy group, and the BLP laminectomy took less time compared to that of the traditional laminectomy (p < 0.05). There was no significant difference in the volume of epidural effusion between the two groups at 2 weeks postoperatively, or in the displacement of the returned vertebral plate observed in sagittal and axial positions. The same was true for the displacement at 3 months postoperatively in the axial position. However, the sagittal displacement in the BLP laminectomy group was smaller than that in the traditional laminectomy group (p < 0.05). CONCLUSIONS: The BLP laminectomy is safe for the resection of thoracolumbar spinal canal tumors. It is less traumatic and faster, with less displacement of the returned lamina, resulting in a stable repair of the spine.

Hypertrophy of paravertebral muscles after epidural electrical stimulation shifted: A case report.

Epidural electrical stimulation (EES) has been used to improve motor function in patients with chronic spinal cord injury (SCI). The effect of EES on paravertebral muscles in patients with SCI has been unnoticed. We reported a case of paravertebral muscles hypertrophy after the electrode shifted in a patient with spinal cord injury. We also discussed possible mechanistic accounts for this occurs.

High platelet count predicts poor prognosis in HCC patients undergoing TACE: a propensity score-matched analysis.

BACKGROUND: The aim of this study was to retrospectively evaluate the prognostic value of the pretreatment platelet (PLT) count in patients with hepatitis B virus (HBV)-related intermediate-advanced hepatocellular carcinoma (HCC) complicated with cirrhosis undergoing transcatheter arterial chemoembolization (TACE). RESEARCH DESIGN AND METHODS: We assessed 362 patients with HBV-related intermediate-advanced HCC complicated with cirrhosis undergoing TACE. Patients were divided into low (≤96 × 109/L) and high (>96 × 109/L) PLT groups. Propensity score matching (PSM) was performed to eliminate the imbalance in potential confounding factors. The endpoint was time to progression (TTP). RESULTS: After PSM, the high and low PLT groups had 97 patients each. The TTP was significantly longer in the low PLT group than in the high PLT group (log-rank test, p < 0.001). A high pretreatment PLT count was an independent predictor of poor tumor response (OR 4.724; 95% CI 1.889-11.815; P = 0.001) and short TTP (HR = 3.598; 95% CI: 2.570-5.036; P < 0.001). Subgroup analysis showed that a high PLT count increased the risk of progression across almost all subgroups. CONCLUSIONS: The pretreatment PLT count has potential value in predicting the prognosis of patients with intermediate-advanced HCC undergoing TACE.

A Candidate Secreted Effector Protein of Rubber Tree Powdery Mildew Fungus Contributes to Infection by Regulating Plant ABA Biosynthesis.

Powdery mildew infects a wide range of crops and economic plants, causing substantial losses. Rubber trees (Hevea brasiliensis) are the primary source of natural rubber, and powdery mildew infection causes significant losses to natural rubber yields. How the causal agent, Erysiphe quercicola, establishes successful infection in rubber trees is largely unknown. Previously, 133 candidate secreted effector proteins (CSEPs) were identified in powdery mildew fungus. In this study, we characterize a CSEP named EqCSEP01276 for its function in suppressing host plant defense responses. We show that EqCSEP01276 is a secreted protein and is able to disturb the localization of 9-cis-epoxycarotenoid dioxygenase 5 (HbNCED5), a key enzyme in abscisic acid (ABA) biosynthesis in plant cell chloroplasts of H. brasiliensis. We also show that this effector inhibits ABA biosynthesis, and that in H. brasiliensis ABA is a positive regulator of the plant immune response against powdery mildew. Our study reveals a strategy by which powdery mildew fungus manipulates plant ABA-mediated defense for a successful infection.

Characterization and elimination of artificial non-covalent light Chain dimers in reduced CE-SDS analysis of pertuzumab.

Capillary electrophoresis sodium dodecyl sulfate (CE-SDS), either in reduced (rCE-SDS) or non-reduced (nrCE-SDS) form, is widely used for purity evaluation and impurity analysis of monoclonal antibody (mAb) drugs. The accuracy of the method may be interfered by artificial species resulted from sample preparation or electrophoresis operation if it is not well optimized. In a routine analysis of pertuzumab for both innovator Perjeta® and biosimilar HLX11 samples, a cluster of unknown peaks located between light chain (LC) and heavy chain (HC) were observed in rCE-SDS and making the purity of (LC + HC)% unacceptable. They can hardly be reduced by regular method optimization such as changing buffer pH, denaturing temperature or incubation time to achieve the (LC + HC)% expectation. Here, the peaks are first characterized and determined to be non-covalently formed LC-LC dimers by multiple techniques including reversed-phase liquid chromatography-mass spectrometry (LC-MS). These artifacts are then eliminated through enhancing capillary separation temperature to 60 °C and decreasing the separation voltage to 9.5 kV, an unusual CE-SDS operation setting. Finally, a developed rCE-SDS method is presented for successful evaluation of pertuzumab purity and impurities, which is further confirmed by an alternative reduced microchip-based gel electrophoresis. In summary, the developed method provided an accurate and reliable purity evaluation and size variant profiling for batch releasing, stability testing and quality study of reduced pertuzumab samples.

Demonstrating Analytical Similarity of Trastuzumab Biosimilar HLX02 to Herceptin® with a Panel of Sensitive and Orthogonal Methods Including a Novel FcγRIIIa Affinity Chromatography Technology.

BACKGROUND: A biosimilar needs to demonstrate its similarity to the originator reference product (RP) in terms of structural and functional properties as well as nonclinical and clinical outcomes. OBJECTIVES: The aim was to assess the analytical similarity between the trastuzumab biosimilar HLX02 and Europe-sourced Herceptin® (EU-Herceptin®) and China-sourced Herceptin® (CN-Herceptin®) following a quality-by-design (QbD) quality study and tier-based quality attribute evaluation. METHODS: A panel of highly sensitive and orthogonal methods, including a novel Fc gamma receptor IIIa (FcγRIIIa) affinity chromatography technique that enables quantitative comparison of glycan effects on effector function, was developed for the assessment. To ensure the full product variability was captured, ten batches of HLX02 were compared with 39 RP batches with expiry dates from August 2017 to March 2021. RESULTS: The extensive three-way similarity assessment demonstrated that HLX02 is highly similar to the RPs. Furthermore, the %afucose, %galactose, and FcγRIIIa affinity of the RPs were observed to first decrease and then return to the original level in relation to their expiry dates, and the RP batches can be subgrouped by their FcγRIIIa affinity chromatograms. HLX02 is demonstrated to be more similar to the RPs of the high FcγRIIIa affinity group. CONCLUSION: Besides having an overall high analytical similarity to both EU-Herceptin® and CN-Herceptin®, HLX02 is more similar to Herceptin® with high FcγRIIIa affinity, a result that demonstrates the power of the novel FcγRIIIa affinity chromatography technology in biosimilarity evaluation.

Detection of Germline Mutations of the SMARCB1 Gene in a Chinese Family with Intraspinal Schwannomatosis.

BACKGROUND: Schwannomatosis is the third subtype of neurofibromatosis. Because the tumor is multiple and prone to recurrence, it often brings challenges to clinical diagnosis and treatment. In the past decade, researchers have come to realize the relationship between the SMARCB1 gene and schwannomatosis, which is expected to improve the current level of diagnosis and treatment. CASE DESCRIPTION: We collected the clinical data of intraspinal schwannomatosis in the same family, which is rare, and carried out the genetic tests on 3 generations of family members (N = 25). We found that 8 family members had germline mutations of the SMARCB1 gene, manifested as mutation at the splice site between SMARCB1 gene exon 8 and 9 (c.1118 + 1G > A). CONCLUSIONS: The structural and functional abnormalities of proteins caused by the mutations of the SMARCB1 gene may be the molecular basis for the pathogenesis of schwannomatosis in this family. This study may provide clues for the study of schwannomatosis in the future.

Malignant Peripheral Nerve Sheath Tumor Arising in Schwannomatosis with Multiple Lung Metastases.

BACKGROUND: Malignant peripheral nerve sheath tumor (MPNST) is a kind of rare neurogenic malignancy, which usually arises from nerve fibers in any tissue and organ that have nerve fiber distributions, especially the trunk and extremities, but it is extremely rare in spinal canal. CASE DESCRIPTION: We report a 30-year-old woman who had a history of excision of intraspinal occupying lesions 5 times and the pathologic diagnosis based on histomorphologic and immunohistochemistry was schwannomatosis, which existed in her family history. Unfortunately, she died because her condition deteriorated rapidly and appeared multiple lung metastases. MPNST was confirmed by needle biopsy of lung lesions. CONCLUSIONS: Many cases of MPNST usually developed from neurofibromatosis type 1. However, the incidence of MPNST arising from schwannomatosis was extremely rare. More significantly, using genetic testing on her, we found a splice site mutation (c.1118+1G>A) that occurred between exons 8 and 9 of the SMARCB1 gene, which was first found in this MPNST patient and could lay the foundation for further study of its pathogenesis.

Management of Dumbbell and Paraspinal Tumors of the Thoracic Spine Using a Single-stage Posterolateral Approach: Case Series.

This study investigated the surgical results of a single-stage posterolateral approach with arc incision, unilateral laminectomy, and costotransversectomy for the management of dumbbell tumors and paraspinal tumors of the thoracic spine. From January 2010 to March 2017, 14 patients with dumbbell tumors or paraspinal tumors of the thoracic spine who underwent resection with single-stage posterolateral approach were followed up and analyzed retrospectively. The operations were performed using a single-stage posterolateral approach with arc incision, unilateral laminectomy, and costotransversectomy without any instrumentation. We reviewed the scores of clinical symptoms and imaging results, including postoperative MRI and reconstructed 3D-CT images. Gross total removal was achieved in 13 patients, and subtotal removal was achieved in 1 case. Histopathology revealed schwannoma in 9 patients, angiolipoma in 1 patient, and paraganglioma and mixed hemangioma in 2 patients each. No significant operative or postoperative complications occurred in any patient. The 14 patients were followed up for 14-68 months (mean 39.4 months). At the final follow-up, no obvious spinal deformity or tumor recurrence was found in any patient except one with paraganglioma. Single-stage posterolateral approach is a good alternative surgical method for removing dumbbell tumors and paraspinal tumors of the thoracic spine without necessitating a subsequent anterior operation.

Metal-Chelate Affinity Precipitation with Thermo-Responsive Polymer for Purification of ε-Poly-L-Lysine.

ε-Poly-L-lysine (ε-PL) is a natural preservative for food processing industry. A thermo-responsive polymer, attached with Cu2+ or Ni2+, was prepared for metal-chelate affinity precipitation for purification of ε-PL. The low critical solution temperatures (LCSTs) of these polymers were close to the room temperature (31.0-35.0 °C). The optimal adsorption conditions were as follows: pH 4.0, 0 mol/L NaCl, ligand density 75.00 µmol/g, and 120 min. The ligand Cu2+ showed a stronger affinity interaction with ε-PL and the highest adsorption amount reached 251.93 mg/g polymer. The elution recovery of ε-PL could be 98.42% with 0.50 mol/L imidazole (pH = 8.0) as the eluent. The method could purify ε-PL from fermentation broth and the final product was proved as electrophoretic pure by SDS-PAGE. Moreover, these affinity polymers could be recycled after the purification of ε-PL and the recoveries were above 95.00%. Graphical Abstract Scheme for affinity precipitation of ε-PL.

Separation of transglutaminase by thermo-responsive affinity precipitation using l-thyroxin as ligand.

Transglutaminase (TGase) is widely used in the food industry. In this study, TGase was purified by affinity precipitation using l-thyroxin, coupled to a thermo-responsive polymer (PNBN), as an affinity ligand. The lower critical solution temperature and recovery of the affinity polymer were 31.0 °C and 99.6 %, respectively. The optimal adsorption condition was 0.02 mol/L phosphate buffer (pH 5.0). The recoveries 99.01 % (protein) and 98.85 % (activity) were obtained by 0.2 mol/L Gly-NaOH buffer (pH 10.0) as the elution agent. Circular dichroism spectroscopy and FortéBio Octet system were used to explore the interactions between l-thyroxin and TGase. The results show that l-thyroxin is suitable for affinity precipitation of TGase. The purity of the final product was verified using sodium dodecyl sulfate polyacrylamide gel electrophoresis.

Microbial Transglutaminase Separation by pH-Responsive Affinity Precipitation with Crocein Orange G as the Ligand.

A microbial transglutaminase (MTG) was efficiently purified by using pH-responsive affinity precipitation with Crocein orange G (COG) as the affinity ligand. The docking method was used to identify the appropriate ligand. The molecular simulation results were compared with the label-free detection data analyzed by ForteBio's Octet. A pH-responsive polymer, PMMDN, was polymerized and subsequently coupled with COG as the ligand. The isoelectric point (pI) and recovery of PMMDN and PMMDN-COG were 4.51, 99.8,% and 4.78, 98.1 %, respectively. The optimal adsorption conditions were found to be a ligand density of 60.0 µmol/g, pH 7.0, and 0.2 mol/L NaCl. The adsorption isotherm showed that the maximum adsorption capacity was 91.32 mg/g polymer and the dissociation constant was 0.021 mg/mL. Interaction information between PMMDN-COG and MTG in the whole process of affinity precipitation were obtained by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). PB (0.02 mol/L pH 7.0) in 20.0 % glycol was used to elute the binding MTG from PMMDN-COG. Under these conditions, electrophoretically pure MTG was obtained in only one step with elution recoveries of 98.96 % (protein) and 95.09 % (activity).

Sequential one-pot enzymatic synthesis of oligo-N-acetyllactosamine and its multi-sialylated extensions.

A simple and efficient protocol for the preparative-scale synthesis of various lengths of oligo-N-acetyllactosamine (oligo-LacNAc) and its multi-sialylated extensions is described. The strategy utilizes one thermophilic bacterial thymidylyltransferase (RmlA) coupled with corresponding sugar-1-phosphate kinases to generate two uridine diphosphate sugars, UDP-galactose and UDP-N-acetylglucosamine. By incorporating glycosyltransferases, oligo-LacNAcs and their sialylated analogs were synthesized.