Enhanced production of cytidine 5'-monophosphate using biocatalysis of di-enzymes immobilized on amino-functionalized sepharose

Cytidine 5'-monophosphate(5'-CMP)is an essential nucleotide for additives.In this study,enhanced production of 5'-CMP was realized by the transformation of cytidine using co-immobilized di-enzymes,uridine-cytidine kinase(UCK)and acetate kinase(AcK).The immobilization yield of the enzyme had a clear correlation with the surface charges as zeta potential(ξ).Among them,ε-polylysinefunctionalized sepharose(SA-EPL,ξ=9.31 m V)showed high immobilization yield(78.8%),which was4.9-fold than that of nitrilotriacetic acid functionalized sepharose(SA-NTA,ξ=-12.6 m V).The residual activity of affinity co-immobilized enzyme(EPL-Ni/EPL@Ac K-UCK)was higher than 70.6%after recycled 10 times.Thus,this study provides an effective approach for the production of 5'-CMP with the advantages of low adenosine 5'-triphosphate(ATP)consumption,reduced side reactions,and improved reusability by co-immobilized UCK and Ac K on the functionalized Sepharose.

双核Pt(Ⅳ)配合物与Guanosine-5′-Monophosphate和Glutathione反应的核磁共振光谱研究(英文)

合成了一个新型的双核Pt(Ⅳ)配合物｛[cis-Pt(NH3)2Cl(OH)2]2(4,4′-methylenedianiline)｝(NO3)2(化合物1)及相应的15N标记化合物｛[cis-Pt(15NH3)2Cl(OH)2]2(4,4′-methylenedianiline)｝(NO3)2(化合物15N-1)。利用1HNMR和ESMS进行了结构表征,化合物15N-1的2D[1H,15N]HSQCNMR发现,该化合物在水溶液中存在同分异构体。2D[1H,15N]HSQCNMR技术跟踪了化合物15N-1与Guanosine-5′-Monophosphate(5′-GMP)和Glutathione(GSH)的反应。结果显示,5′-GMP能在0.5h内将化合物1还原,而GSH在6h以后才能够部分的将化合物1还原。化合物1所表现出来的反应性能将有利于提高其治疗效果和降低毒副作用。

STUDY ON THE MECHANISM OF INTERFERON ACTION (Ⅺ)——EFFECT OF pppA2'p5'A2'p5'A ON THE LEVEL OF cAMP AND cGMP IN MACROPHAGES

In this paper, the increase of cellular cAMP and cGMP levels in macrophages induced bypppA2’p5’A2’p5’A （briefly 2’-5’P3A3） is first reported. The optimal concentration of 2’-5’P3A3 for the elevation of cellular cGMP to the highest level is 10-7-10-6mol/L, while thatfor cAMP is 10-7mol/L. The time for cGMP to reach its peak value is 15 min and that forcAMP is 2 h, when the cells are treated with 2’-5’ P3A3 at 10-7mol/L, which is the optimalconcentration for developing biological effect of macrophages （phagocytosis）. These resultssuggest that cGMP and cAMP may be related to, or may be the mediators for, 2’-5’P3A3action.

Electrocatalysis Oxidation of GMP Based on Layered Double Hydroxide Functionalized with Anionic Surfactant and Room Temperature Ionic Liquid Modified Glassy Carbon Electrode

The electrocatalysis oxidation of guanosine-5＇-monophosphate （GMP） was investigated on Mg-AI layered double hydroxide （LDH） functionalized with sodium dodecyl sulfate （SDS） and room temperature ionic liquid （RTIL） modified glass carbon electrode （GCE）. The cyclic voltammogram of GMP on the modified electrode （RTIL/ LDH-SDS/GCE） exhibited a well defined anodic peak at 1.091 V in 0.2 moloL ^-1 pH 4.4 acetate buffer solution. The GMP oxidation was enhanced in the presence of anionic surfactant in the films. The results suggest that the surfactant molecules intercalate the LDH layers to preconcentrate GMP molecules and the RTIL showed good ionic conductivity. The experimental parameters were optimized, the kinetic parameters were investigated and the probable oxidation mechanism was proposed. Under the optimized conditions, the oxidation peak current was proportional to GMP concentration in the range from 5.0 × 10^-7 to 1.0×10^-4 mol·L ^-1with the correlation coefficient of 0.9987 and the detection limit was 1.0 × 10 7 mol·L^-1, The RTIL/LDH-SDS/GCE showed a good electrochemical response to the oxidation of GMP and would be developed into a new biosensor.

Effects of catecholamine-β-adrenoceptor-cAMP system on severe patients with heart failure

Objective To investigate the association between catecholamine-β-adrenoceptor (β-AR)-adenosine 3’,5’-monophosphate (cAMP) system and long-term prognosis in patients with chronic heart failure (CHF).Methods The study population comprised 73 patients with CHF (EF: 23%±10%) with a mean follow-up of 3.8±1.9 years. Plasma levels of norepinephrine (NE) were measured using high performance lipid chromatography,β-adrenergic receptor density (Bmax) and the content of cAMP in peripheral lymphocytes were calculated using 3H-dihydroalpneolo as ligand and competitive immunoassay,respectively. Deaths due to cardiovascular events within the follow-up period were registered.Results The total mortality was 64.7%,57.4% of which was for cardiogenic (worsening heart failure: 32.4%; sudden death: 25.0%). In the cardiogenic death group,plasma levels of NE and epinephrine (E) (3.74 nmol/L±0.09 nmol/L and 3.17 nmol/L±1.0nmol/L) and the contents of peripheral lymphocyte cAMP (3.64 pmol/mg protein±1.4 pmol/mg protein) were significantly increased as compared with the survival group (2.68 nmol/L±0.07 nmol/L,2.41 nmol/L±0.24 nmol/L and 2.73 pmol/mg protein±0.9 pmol/mg protein,respectively,all P <0.01). In the sudden death group,plasma levels of NE and E (5.01 nmol/L±0.06 nmol/L and 4.13 nmol/L±0.08 nmol/L) were significantly increased as compared with the worsening heart failure group (2.49 nmol/L±0.07 nmol/L and 2.33 nmol/L±0.8 nmol/L,all P <0.001) and to the survival group (2.68 nmol/L±0.07 nmol/L and 2.41 nmol/L±0.14 nmol/L,all P <0.01). The incidences of sudden death were 0%,75%,and 100% (χ 2=16.018, P <0.01) in patients with plasma NE<2.5 nmol/L,NE 2.5 nmol/L-4.5 nmol/L,and NE>4.5 nmol/L,respectively. In the worsening heart failure group,the content of peripheral lymphocyte cAMP (4.46 pmol/mg protein±0.18 pmol/mg protein) was significantly increased compared with the sudden death group (2.39 pmol/mg protein±0.9 pmol/mg protein,P <0.001) and to the survival group (2.73 pmol/mg protein±1.1 pmol/mg protein,P <0.001). The worsening heart failure death occurences were 5.0%,72.2%,and 100% (χ 2=14.26,P <0.01) in patients with a content of peripheral lymphocyte cAMP <2.5 nmol/L,cAMP 2.5 nmol/L-4.5 nmol/L,and cAMP>4.5nmol/L,respectively. B max in peripheral lymphocyte was not significantly different ( P >0.05) among the sudden death,worsening heart failure,and survival groups in CHF patients.Conclusions Plasma levels of catecholamine increase significantly,and B max and the contents of cAMP in peripheral lymphocytes decrease significantly in patients with CHF. High plasma catecholamine levels may be associated with sudden death,and high intralymphocyte cAMP content may be associated with worsening heart failure in CHF patients.