Chemical modifications can potentially change monoclonal antibody's (mAb) local or global conformation and therefore impact their efficacy as therapeutic drugs. Modifications in the complementarity-determining regions (CDRs) are especially important because they can impair the binding affinity of an antibody for its target and therefore drug potency as a result. In order to understand the impact on mAb attributes induced by specific chemical modifications within the CDR, hydrogen-deuterium exchange mass spectrometry (HDX MS) was used to interrogate the conformational impact of Asp isomerization and Met oxidation in the CDRs of a model monoclonal antibody (mAb1). Our results indicate that despite their proximity to each other, Asp54 isomerization and Met56 oxidation in CDR2 in the heavy chain of mAb1 result in opposing conformational impacts on the local and nearby regions, leading directly to different alterations on antibody-antigen binding affinity. This study revealed direct evidence of local and global conformational changes caused by two of the most common degradation pathways in the CDRs of a mAb and identified correlations between chemical modification, structure, and function of the therapeutic monoclonal antibody.
In order to reduce the temperature of paraffin-based crude oil,is applied low-temperature dehydration performance of the AE8051, is the good effects of high viscosity crude oil dehydration polyether polyol-based SAA and polyoxyethylene polyoxypropylene glycol ether BP28 for "coordination" recovery distribution is also applied. As result , a small amount of C-F surfactant will make the system active and increase the solubility of paraffin-based demulsifier in crude oil at low temperature FYR-015. The basic formula, which by low-temperature synthesis of a series of demulsifier samples at concentration of 200mg / L(in water) and 30% of the joint stand of the mixed oil at 40 °C, has been the relative dehydration rates of 90 minutes over 93% of the 3 a formula of low-temperature demulsifier, the dual temperature demulsifier compound obtained in the same temperature, the same dosage effect of the case of dehydration and a single dose equivalent in dosage trials are three formulations of low temperature demulsifier in 40 °C are the best dosage 100mg / L. Xuanze solid content of 55% of finished emulsion breaker formulation 5 into field use, dosage to 60 mg / L when the water content of crude oil were isolated less than 0.2%, to reach the standard of foreign crude oil output quality, extrusion sewage oil is less than 50 mg / L, water clear.
To solve the single tube gathering process paraffin oil viscosity reduction shaft and gathering the problem of high back pressure. Technical application of crude oil pour point depressant, mixed ester, benzene, ethylene oxide such as octylphenol ether compound by an oil-soluble DRA. Dosage in the 50 ~ 100mg/l to meet the water when the wellbore is less than 25% of the wax viscosity and single-tube process requirements gathering, can be compared to the multi-port wells, monitoring data before and after dosing showed that the crude oil after dosing freezing point decreased 5.6 °C, the average rate of 87.4% viscosity reduction, the average rate of 91.5% paraffin. Pipeline wellhead back pressure reduced by 20 to 30 percentage points
When CaCL2 or CaBr2 solution is used to kill the well during the pump check process,the productivity of the oil well becomes unstable. The developed FRY surfactant that a nonionic polyether surfactant is used as main material and compounded with various anionic and zwitterionic surfactants could solve this problem. The results show it has excellent foamy characteristic and wettability, and can eliminate the alkali and water sensitization of stratum under acidic condition. The FRY surfactant has been successfully applied to the plugging relief of oil well. The synthesis, performance evaluation and field application of the FRY surfactant are introduced in the paper.
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