Protein A

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Susanne Ruge - One of the best experts on this subject based on the ideXlab platform.

  • humAn plAcentAl lActogen And pregnAncy AssociAted plAsmA Protein A in first trimester And subsequent fetAl growth
    Acta Obstetricia et Gynecologica Scandinavica, 1995
    Co-Authors: Jan Fog Pedersen, Steen Sørensen, Susanne Ruge
    Abstract:

    Objective. To study in An optimized design the possible relAtion between serum levels in weeks 8-14 of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A And fetAl size At delivery.Methods. AnAlysis of dAtA from 93 normAl singleton pregnAncies. GestAtionAl Age wAs Assessed from A sonogrAphic crown-rump length meAsurement. Serum levels of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A were determined by rAdioimmunoAssAy, And were expressed in multiples of meAn. The relAtive birth weight wAs used As An index of fetAl growth.Results. Serum levels of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A showed A negAtive correlAtion to gestAtionAl Age At delivery (p<0.01 Andp<0.05, respectively), And there wAs A positive correlAtion between the serum level of pregnAncy-AssociAted plAsmA Protein A And relAtive birth weight (p<0.02).Conclusions. Higher levels of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A predicted eArlier delivery, mAybe b...

  • HumAn plAcentAl lActogen And pregnAncy‐AssociAted plAsmA Protein A in first trimester And subsequent fetAl growth
    Acta Obstetricia et Gynecologica Scandinavica, 1995
    Co-Authors: Jan Fog Pedersen, Steen Sørensen, Susanne Ruge
    Abstract:

    Objective. To study in An optimized design the possible relAtion between serum levels in weeks 8-14 of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A And fetAl size At delivery.Methods. AnAlysis of dAtA from 93 normAl singleton pregnAncies. GestAtionAl Age wAs Assessed from A sonogrAphic crown-rump length meAsurement. Serum levels of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A were determined by rAdioimmunoAssAy, And were expressed in multiples of meAn. The relAtive birth weight wAs used As An index of fetAl growth.Results. Serum levels of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A showed A negAtive correlAtion to gestAtionAl Age At delivery (p

  • HumAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A in first trimester And subsequent fetAl growth
    Acta Obstetricia et Gynecologica Scandinavica, 1995
    Co-Authors: Jan Fog Pedersen, Steen Sørensen, Susanne Ruge
    Abstract:

    Objective. To study in An optimized design the possible relAtion between serum levels in weeks 8-14 of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A And fetAl size At delivery.Methods. AnAlysis of dAtA from 93 normAl singleton pregnAncies. GestAtionAl Age wAs Assessed from A sonogrAphic crown-rump length meAsurement. Serum levels of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A were determined by rAdioimmunoAssAy, And were expressed in multiples of meAn. The relAtive birth weight wAs used As An index of fetAl growth.Results. Serum levels of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A showed A negAtive correlAtion to gestAtionAl Age At delivery (p

Steven M. Cramer - One of the best experts on this subject based on the ideXlab platform.

  • Improved process AnAlyticAl technology for Protein A chromAtogrAphy using predictive principAl component AnAlysis tools
    Biotechnology and Bioengineering, 2011
    Co-Authors: Ying Hou, Canping Jiang, Abhinav A Shukla, Steven M. Cramer
    Abstract:

    Protein A chromAtogrAphy is widely employed for the cApture And purificAtion of Antibodies And Fc-fusion Proteins. Due to the high cost of Protein A resins, there is A significAnt economic driving force for using these chromAtogrAphic mAteriAls for A lArge number of cycles. The mAintenAnce of column performAnce over the resin lifetime is Also A significAnt concern in lArge-scAle mAnufActuring. In this work, severAl stAtisticAl methods Are employed to develop A novel principAl component AnAlysis (PCA)-bAsed tool for predicting Protein A chromAtogrAphic column performAnce over time. A method is developed to cArry out detection of column integrity fAilures before their occurrence without the need for A sepArAte integrity test. In Addition, AnAlysis of vArious trAnsitions in the chromAtogrAms wAs Also employed to develop PCA-bAsed models to predict both subtle And generAl trends in reAl-time Protein A column yield decAy. The developed ApproAch hAs significAnt potentiAl for fAcilitAting timely And improved decisions in lArge-scAle chromAtogrAphic operAtions in line with the process AnAlyticAl technology (PAT) guidAnce from the Food And Drug AdministrAtion (FDA).

  • Antibody vAriAble region interActions with Protein A implicAtions for the development of generic purificAtion processes
    Biotechnology and Bioengineering, 2005
    Co-Authors: Sanchayita Ghose, Brian Hubbard, Clayton A Brooks, Martin J. Allen, Steven M. Cramer
    Abstract:

    In this pAper, A wide rAnge of Antibodies from vArious subclAsses And subfAmilies Are employed to evAluAte the creAtion of generic sepArAtion processes using Protein A chromAtogrAphy. The reAsons for elution pH differences Amongst severAl IgG1s, IgG2s, Antibody frAgments, And Fc-fusion Proteins during Protein A chromAtogrAphy Are investigAted using severAl complimentAry techniques. The results indicAte thAt vAriAble region interActions plAy A mAjor role in determining elution pH for VH3 subfAmily Antibodies while using trAditionAl Protein A chromAtogrAphic mAteriAls. On the other hAnd, experiments with A resin which employs A ligAnd consisting solely of B domAin of Protein A indicAte thAt vAriAble region interActions cAn be mitigAted, enAbling the use of A single elution pH for A rAnge of Antibodies. FinAlly, the moderAtion of elution conditions AssociAted with this engineered ligAnd Are shown to minimize problems AssociAted with low pH induced AggregAtion. It is expected thAt the findings reported in this pAper will fAcilitAte fAster process development cycle times for this importAnt clAss of humAn therApeutics. © 2005 Wiley PeriodicAls, Inc.

Abhinav A Shukla - One of the best experts on this subject based on the ideXlab platform.

  • Improved process AnAlyticAl technology for Protein A chromAtogrAphy using predictive principAl component AnAlysis tools
    Biotechnology and Bioengineering, 2011
    Co-Authors: Ying Hou, Canping Jiang, Abhinav A Shukla, Steven M. Cramer
    Abstract:

    Protein A chromAtogrAphy is widely employed for the cApture And purificAtion of Antibodies And Fc-fusion Proteins. Due to the high cost of Protein A resins, there is A significAnt economic driving force for using these chromAtogrAphic mAteriAls for A lArge number of cycles. The mAintenAnce of column performAnce over the resin lifetime is Also A significAnt concern in lArge-scAle mAnufActuring. In this work, severAl stAtisticAl methods Are employed to develop A novel principAl component AnAlysis (PCA)-bAsed tool for predicting Protein A chromAtogrAphic column performAnce over time. A method is developed to cArry out detection of column integrity fAilures before their occurrence without the need for A sepArAte integrity test. In Addition, AnAlysis of vArious trAnsitions in the chromAtogrAms wAs Also employed to develop PCA-bAsed models to predict both subtle And generAl trends in reAl-time Protein A column yield decAy. The developed ApproAch hAs significAnt potentiAl for fAcilitAting timely And improved decisions in lArge-scAle chromAtogrAphic operAtions in line with the process AnAlyticAl technology (PAT) guidAnce from the Food And Drug AdministrAtion (FDA).

  • host cell Protein cleArAnce during Protein A chromAtogrAphy development of An improved column wAsh step
    Biotechnology Progress, 2008
    Co-Authors: Abhinav A Shukla, Peter Hinckley
    Abstract:

    Host cell Protein (HCP) contAminAnt cleArAnce is A significAnt concern during downstreAm process development for biophArmAceuticAls. Protein A chromAtogrAphy As A cApture step for monoclonAl Antibodies And Fc fusion Proteins cAn cleAr A lArge proportion of these impurities from cell culture hArvest. Nevertheless, remAining levels of this process-relAted impurity clAss do present significAnt constrAints on the rApid development of effective And robust polishing steps. ConventionAlly, An intermediAte pH wAsh is employed between column loAding And elution to minimize HCP levels After Protein A chromAtogrAphy. A significAnt mechAnistic finding presented in this work is thAt HCP contAminAnts thAt persist following Protein A cApture predominAntly comprise species thAt AssociAte with the product in preference to direct interAction with the chromAtogrAphic resin. This suggests thAt the development of improved column wAsh techniques to mAximize HCP cleArAnce ought to focus on disrupting Protein–HCP interActions rAther thAn Protein A–HCP interActions. A higher wAsh pH to preserve product – Protein A binding Along with the use of Additive combinAtions to disrupt interActions between HCPs And the product Are investigAted. This strAtegy wAs successfully Applied to develop A broAdly ApplicAble wAsh condition thAt hAs the potentiAl for eliminAting the need for product specific optimizAtion of wAsh conditions. A combinAtion of 1 M ureA And 10% isopropAnol in the wAsh buffer were successfully Applied As A plAtform wAsh condition for Protein A chromAtogrAphy. Use of this (And other similAr) wAsh conditions Are AnticipAted to Aid the rApid development of effective downstreAm processes for monoclonAl Antibodies And Fc fusion Proteins resulting in their rApid introduction into clinicAl triAls.

J. Christopher Hall - One of the best experts on this subject based on the ideXlab platform.

  • PurificAtion of the therApeutic Antibody trAstuzumAb from geneticAlly modified plAnts using sAfflower Protein A-oleosin oilbody technology.
    Transgenic Research, 2012
    Co-Authors: Michael D. Mclean, Rongji Chen, John Teat, Steve Zaplachinski, Joseph Boothe, Deqiang Yu, Haifeng Wang, J. Christopher Hall
    Abstract:

    Production of therApeutic monoclonAl Antibodies using geneticAlly modified plAnts mAy provide low cost, high scAlAbility And product sAfety; however, Antibody purificAtion from plAnts presents A chAllenge due to the lArge quAntities of biomAss thAt need to be processed. Protein A column chromAtogrAphy is widely used in the phArmAceuticAl industry for Antibody purificAtion, but its ApplicAtion is limited by cost, scAlAbility And column fouling problems when purifying plAnt-derived Antibodies. Protein A-oleosin oilbodies (Protein A-OB), expressed in trAnsgenic sAfflower seeds, Are relAtively inexpensive to produce And provide A new ApproAch for the cApture of monoclonAl Antibodies from plAnts. When Protein A-OB is mixed with crude extrActs from plAnts engineered to express therApeutic Antibodies, the Protein A-OB cAptures the Antibody in the oilbody phAse while impurities remAin in the Aqueous phAse. This is followed by repeAted pArtitioning of oilbody phAse AgAinst An Aqueous phAse viA centrifugAtion to remove impurities before purified Antibody is eluted from the oilbodies. We hAve developed this purificAtion process to recover trAstuzumAb, An Anti-HER2 monoclonAl Antibody used for therApy AgAinst specific breAst-cAncers thAt over express HER2 (humAn epidermAl growth fActor receptor 2), from trAnsiently infected NicotiAnA benthAmiAnA. Protein A-OB overcomes the fouling problem AssociAted with trAditionAl Protein A chromAtogrAphy, Allowing for the development of An inexpensive, scAlAble And novel high-resolution method for the cApture of Antibodies bAsed on simple mixing And phAse sepArAtion.

Jan Fog Pedersen - One of the best experts on this subject based on the ideXlab platform.

  • humAn plAcentAl lActogen And pregnAncy AssociAted plAsmA Protein A in first trimester And subsequent fetAl growth
    Acta Obstetricia et Gynecologica Scandinavica, 1995
    Co-Authors: Jan Fog Pedersen, Steen Sørensen, Susanne Ruge
    Abstract:

    Objective. To study in An optimized design the possible relAtion between serum levels in weeks 8-14 of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A And fetAl size At delivery.Methods. AnAlysis of dAtA from 93 normAl singleton pregnAncies. GestAtionAl Age wAs Assessed from A sonogrAphic crown-rump length meAsurement. Serum levels of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A were determined by rAdioimmunoAssAy, And were expressed in multiples of meAn. The relAtive birth weight wAs used As An index of fetAl growth.Results. Serum levels of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A showed A negAtive correlAtion to gestAtionAl Age At delivery (p<0.01 Andp<0.05, respectively), And there wAs A positive correlAtion between the serum level of pregnAncy-AssociAted plAsmA Protein A And relAtive birth weight (p<0.02).Conclusions. Higher levels of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A predicted eArlier delivery, mAybe b...

  • HumAn plAcentAl lActogen And pregnAncy‐AssociAted plAsmA Protein A in first trimester And subsequent fetAl growth
    Acta Obstetricia et Gynecologica Scandinavica, 1995
    Co-Authors: Jan Fog Pedersen, Steen Sørensen, Susanne Ruge
    Abstract:

    Objective. To study in An optimized design the possible relAtion between serum levels in weeks 8-14 of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A And fetAl size At delivery.Methods. AnAlysis of dAtA from 93 normAl singleton pregnAncies. GestAtionAl Age wAs Assessed from A sonogrAphic crown-rump length meAsurement. Serum levels of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A were determined by rAdioimmunoAssAy, And were expressed in multiples of meAn. The relAtive birth weight wAs used As An index of fetAl growth.Results. Serum levels of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A showed A negAtive correlAtion to gestAtionAl Age At delivery (p

  • HumAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A in first trimester And subsequent fetAl growth
    Acta Obstetricia et Gynecologica Scandinavica, 1995
    Co-Authors: Jan Fog Pedersen, Steen Sørensen, Susanne Ruge
    Abstract:

    Objective. To study in An optimized design the possible relAtion between serum levels in weeks 8-14 of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A And fetAl size At delivery.Methods. AnAlysis of dAtA from 93 normAl singleton pregnAncies. GestAtionAl Age wAs Assessed from A sonogrAphic crown-rump length meAsurement. Serum levels of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A were determined by rAdioimmunoAssAy, And were expressed in multiples of meAn. The relAtive birth weight wAs used As An index of fetAl growth.Results. Serum levels of humAn plAcentAl lActogen And pregnAncy-AssociAted plAsmA Protein A showed A negAtive correlAtion to gestAtionAl Age At delivery (p

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