Synthesis of (S)-4-fluorophenylglycine by using immobilized amidase based on metal-organic framework / 生物工程学报

A stable Zr-based metal-organic framework (MOF, UiO-66-NH2) synthesized via micro-water solvothermal method was used to immobilize amidase by using the glutaraldehyde crosslinking method. The effect of immoblization conditions on enzyme immoblization efficiency was studied. An activity recovery rate of 86.4% and an enzyme loading of 115.3 mg/g were achieved under the optimal conditions: glutaraldehyde concentration of 1.0%, cross-linking time of 180 min, and the weight ratio of MOF to enzyme of 8:1. The optimal temperature and optimal pH of the immobilized amidase were determined to be 40 °C and 9.0, respectively, and the Km, Vmax and kcat of the immoblized amidase were 58.32 mmol/L, 16.23 μmol/(min·mg), and 1 670 s⁻¹, respectively. The immobilized enzyme was used for (S)-4-fluorophenylglycine synthesis and the optimal reaction conditions were 300 mmol/L of N-phenylacetyl-4-fluorophenylglycine, 10 g/L of immobilized enzyme loading, and reacting for 180 min at pH 9.0 and 40 °C. A conversion rate of 49.9% was achieved under the optimal conditions, and the conversion rate can be increased to 99.9% under the conditions of enantiomeric excess. The immobilized enzyme can be repeatedly used, 95.8% of its original activity can be retained after 20 cycles.

The clinical application of Protis system in the evaluation of intrathecal IgG synthesis and blood-CSF barrier lesion in patients with neurological diseases / 中华检验医学杂志

Objective To analyze blood-CSF barrier and cerebrospinal intrathecal IgG synthesis in patients of multiple sclerosis, and explore the Protis software, IgG index and IgG synthesis rate in the and evaluation for cerebrospinal intrathecal IgG synthesis and blood-CSF barrier dysfunction. Methods 134 patients with neurological diseases were divided into threes groups, including multiple sclerosis group (34 cases), disease control group(80 cases) and control group(20 cases). IgG and ALB concentration of CSF and blood was detected by BN-Ⅱ. The oligoclonal IgG was detected by immunofixation electrophoresis. The relationship between Protis software results and IgG index or IgG synthesis rate was calculated and analyzed. Results The function of blood-brain barrier was almost normal in multiple sclerosis group,QALB was 4.5×10-3[(3.1-7.6)×10-3], there was no significance compared with control group (D=5.25, P>0.05). there were 31 patients with oligaclonal bands in cerebrospinal fluids in multiple sclerosis group (34 patients) with the positive rate of 91.2%. In multiple sclerosis group the intrethecal IgGIF, IgG index and IgG synthesis rate of 24 hours were 31.25% (11.65%-71.45 %), 0.93% (0.80%-1.04%), 24.25 mg/24 h(15.25-46.15 mg/24 h) ,the results were all higher than that in control group (D=175.5, 112.5,103.4,P<0.05). And in multiple sclerosis group there was no significant difference among the intrethecal IgGIF, IgG index and IgG synthesis rate of 24 hours, the positive rate of oligaclonal bands (P>0.05). In disease control group(80 patients) QALB Was 35.2×10-3[(18.5-55.5)×10-3] ,the result was significantly higher than control group (D=102.7, P<0.05), the oligaclonal bands were all negative, IgG index and IgG synthesis rate of 24 hours were 0.75(0.69-0.82) ,44.29 mg/24 h(20.35-65.98 mg/24 h) were both higher than control group(D=85.6,98.5,P<0.05). In disease control group the positive rate of intrathecal IgGIF, IgG index and IgG synthesis rate of 24 hours were 0 (0/80), 40.0% (32/80), 72.5% (58/80) respectively, IgG index and its positive rate both increased alone with the lesion degree of blood-brain barrier increasing (P<0.05). And there was similar trend in the IgG synthesis rate of 24 hours. There were significant correlations among intrathecal IgGIF, IgG index and IgG synthesis rate of 24 hours in multiple sclerosis group (r=0.788, 0.695 ,P<0.05). However there was no correlation among intrathecal IgGIF, IgG index and IgG synthesis rate of 24 hours in disease control group (r=0.000,P>0.05). Conclusions The Protis software can be used to analyze the intrathecal IgGIF and reflect the actual status of intrathecal IgG synthesis more accurately. Protis software has great application value for clinical diagnosis for nervous system disease.

Assessment on the application value of five auto-antibodies in rheumatoid arthritis diagnosis / 中华检验医学杂志

Objective To investigate the level of five auto-antibodies including MCV and GPI in the serum of RA patients and assess the application value of five auto-antibodies in RA diagnosis.Methods The five auto-antibodies were detected by ELISA in serum samples of 150 patients with RA and 40 healthy controls,32 patients of SLE,30 patients of OA,20 patients of AS,20 patients of SS,20 patients of CTD.Results The positive rates of these five auto-antibodies in RA patients were significantly higher than in other group(X2=88.5,76.0,279.2,88.2,94.8,P＜0.05).Except anti-AKA,there was no the differences in the level of other antibodies among groups(X2=21.9,9.4,20.2,43.2,41.6,P＞0.05).Anti-MCV and anti-GPI has the highest sensitivity(78.0% and 83.3%),while anti-CCP has the highest specificity(97.1%)and anti-AKA has good specificity(96.1%)and lowest sensitivity(49.4%).When two antibodies were detected together,the sensitivity and specificity of MCV/CCP were highest(92.7% and 96.9%).When RF/GPI/CCP were detected together,the sensitivity and specificity were 90.7% and 96.9%,respectively.When RF/MCv/CCP were detected together,the sensitivity and specificity were 94.0% and 96.9%.Conclusions Anti-MCV and anti-GPI has the hishest sensitivity in laboratory diagnosis of RA,while anti-CCP has the highest specificity and anti-AKA have good specificity and lowest sensitivity.The combination detection can decrease the amount of missed diagnosis caused by single test. The combination detection of RF/GPI/CCP and RF/MCV/CCP will improve sensitivity and specificity for diagnosis to the RA patients.