Higher-order structure (HOS) is an important physicochemical property of antibody drugs. The most well-known method for HOS characterization is circular dichroism ( CD ) spectroscopy . Althougl CD spectroscopy can provide robust structural information for low-concentration protein solutions ( 0.1 mg / ml ) , antibody drugs are formulated at concentrations higher than 10 mg / ml Under these conditions , the antibody molecules can exhibit physicochemical properties that differ from those under dilute conditions . Fortunately , evaluation of high concentration solutions can be done via short CD path lengths ( 10 mm ) or using FTIR with ATR . The ability to perform structural characterization of antibodies without dilution is extremely important because intermolecular interactions and changes in the HOS can lead to the formation of aggregates that cause serious Immunogenicity. Secondary structure estimation offers a route to evaluate protein higher order structure , but historically has not worked well on proteins with high amounts of b-sheet such as antibodies.Recently , Micsonai et al developed the Bestsel algorithm that can accurately estimate the secondary structure from a CD spectrum by taking into account parallel-antiparallel orientations of b-strands and the twist of antiparallel b-sheets . Bestsel has the following features : 1 ) high estimation accuracy for a wide range of proteins , including b-strand-rich proteins such as antibodies , 2 ) provides eight types of secondary structure information , 3 ) capabiility to predict protein folding following the CATH classification , and 4 ) open web server . While many academic researchers use the Bestsel web server , researchers in biopharma companies who need to work in a GXP environment have not been able to benefit from Bestsel . To make Bestsel accessible to biopharma , we developed Spectra Manager Ver.2.5 CFR Bestsel as an add-in software for Spectra Manager , a control and analysis platform for JASCO CD spectrometers , which is compatible with GXP. Here , we describe an expanded application of CD spectroscopy for highly concentrated antibodies (undiluted) and report the results of a detailed secondary structure evaluation of antibody drugs using Spectra Manager Ver.2.5 CFR Bestsel.本应用中结论:J-1500 CD光谱仪和Spectra ManagerTM2.5 BeStSel CFR能够跟踪配制抗体药物的详细结构变化。Spectra Manager TM2.5 BeStSel CFR提供符合GxP的环境,并提供符合ALCOA+原则的CSV、ER/ES和Dl。