1. EricWalters 510-432-2529 pixels3d2003@yahoo.com25200 CarlosBee#199 ,Hayward,Ca 94542
SKILLS/EXPERIENCE
Versatile published scientist excelling in independent research and development- I
enjoy intellectual and scientific challenges. I bring over twenty years of diverse and
deep experience in the various aspects of protein science including purification and
characterization (HPLC, MALDI-MS, LC-MS)
HPLC/UPLC Method Development: Developed SEC (standard and organic
phase), Cation Exchange, Reverse Phase (intact and reduced) for Monoclonal
antibodies and hybrid fusion antibodies proteins for characterization and quality
monitoring. Created several novel HPLC methods for important protein components
involved in biosynthesis (Cell Free) of biopharmaceuticals.
Protein purification methods design and optimization, ten years of hands on
purification experience with diverse proteins purified from CHO, yeast, bacteria, and
plants via gravity flow and FPLC (AKTA) columns. Expressed, harvested, purified and
characterized two viral proteins (rNA). Developed one step purification-small scale for
EBVgp350. Created novel quantitative and qualitative HPLC assay for non-purified
EBVgp350 (TDR in progress) Involved in all aspects of HA expression, purification,
and quality assessment.
Viral proteins/Monoclonal Antibodies: Setting up panel of analytical techniques
for quantifying and characterization of product quality for Monoclonal Antibodies
(size, intactness, charge isoforms, glycan profiling, protein A titer analysis. Responsible
for analysis and structural characterization of purification fractions by HPLC, SDS
PAGE (Electrophoresis), ELISA, Western blotting, Mammalian Cell Culture (CHO),Flu
Virus surface proteins (HA/NA), Plasmid Purification (GigaPrep). Currently
developing purification for untagged CMVgB and developing analytical techniques to
assist cell culture development (EBVgp350, RSV) at Medimmune- and to determine
quality and characteristics of various viral receptor proteins (RSV, EBVgp350, etc).
Monoclonal Antibodies: Nine years of assay development and characterization of
monoclonal antibodies proteins in research and cGMP/GLP modes of operation.
Familiar with Softmax, and various HPLC software packages, Excel used for data
analysis, and Word for report generation. Fast learner and excellent independent
thinker. Five years training in cGMP and GLP.
Developed novel enzyme assays to determine activity and specific activity of
purified enzymes. Enzyme mode of action and kinetics determinations from purified
fractions (published), Monoclonal Antibody Analytical Development, structure
analysis (peptide mapping and intact mass), HPLC methods development and
qualification (reverse phase, normal phase, size exclusion, HIC, ion exchange, affinity),
MALDI, LC-MS (mass spectrometry), test method writing, technical development
reports and SOP writing, peptide mapping, degradation pathway characterization.
Working knowledge of cGMP’s related to bio-pharmaceutical development
Protein purification: well versed in native and tagged purification-from cell lysate
to homogeneity via column chromatography and ancillary methods including ultra
2. EricWalters 510-432-2529 pixels3d2003@yahoo.com25200 CarlosBee#199 ,Hayward,Ca 94542
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filtration and concentration.
Enzyme assay development (including pathway based assays) for small molecule
screening, protein conjugation chemistry, biochip multiplexed assay development,
ELISA, active enzyme purification, FPLC, low pressure column chromatography,
electrophoresis, UV/Vis spectrophotometry, Biacore, scientific brainstorming and
trouble shooting. Functional and quantitative enyzyme assay development, peptide
mapping, enzyme kinetics (Vmax, Ki, etc), ELISA (plate and bead based).
Instrumentation (including but not limited to): HPLC, MALDI-Mass Spec, FPLC,
spectrophotomers, spectrofluorometers, scintillation counters, centrifuges,
electrophoresis (PAGE, Western blots), GC, robotics (Biomek), liquid handling,
BiaCore, fluorescence microscopes.
SUMMARY Versatile scientist with over twenty years of bench experience. Strong track record of
working in a cross-functional environment to develop interdisciplinary solutions.
Excellent writing, verbal, and computer skills (MS Word, Excel, and Powerpoint).
EXPERIENCE
03/2012- 10/2015 Sutro BioPharma, South San Francisco, CA.
Scientist/Senior Research Associate (Contract/Permanent): Analytical Development:
hired to introduce and run HPLC methods for quantifying and analyzing quality
attributes for Moloclonal Antibodies (mAbs) including SEC, Cation Exchange, and
Protein A, and Reverse Phase HPLC for several mAb’s. Developed pre-HPLC
flocculation and clarification methods for Cell Free (modified bacterial lysate)
produced Monoclonal antibodies. Created HPLC analytical methods (novel) for
various biosynthetic molecules in the Cell Free mixture and fusion proteins.
Developed Mass Spec (M/S) compatible SEC methods. Advised and assisted Research
on developing HPLC methods for new proteins. Wrote formal SOP’s and qualification
plans for various HPLC Methods.
02/2011- 12/22/2011 Medimmune, Santa Clara, CA. (contract)
Associate Scientist II: Cell culture Development: Harvest, Purification and analysis of 4
recombinant Flu Virus surface proteins- HA (Florida,Perth,California,Brisbane).
Carried out entire process (expression to purification and quality) of 2 NA proteins.
3. EricWalters 510-432-2529 pixels3d2003@yahoo.com25200 CarlosBee#199 ,Hayward,Ca 94542
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Developing analytical methods to characterize purity and quality parameters for
EBVgp350, HA, soluble F, and CMVgB. Setting up panel of quality determining assays
for Monoclonal Antibodies (IgG) including intactness, glycan profiling, charge
isoforms, Protein A titer and others. Maintaining Mammalian (CHO) Cell Cultures,
Bacterial Cell Cultures, GigaPreps (Plasmid Purification) etc.
11/2005- 11/2010 Xoma, LLC , Berkeley, CA.
Senior Research Associate (Associate Scientist): Analytical Development: Responsible for
HPLC Assay Development and analysis of cell harvests and (purification) column
fractions for mammalian and bacterial Monoclonal Antibodies and Fab’s. Developed
test methods for determining Fab titers from bacterial broths and column fractions
including HPLC column, conditions and pre-analysis sample treatment Responsible
for the characterization of numerous Monoclonal Antibodies produced at Xoma
(charge isoforms, post-translational modifications). Developed/introduced glycan
(glycosylation) profiling and antibody peptide mapping techniques utilizing MALDI-
TOF as ancillary methodologies for CE and HPLC-MS. Developed HPLC and Mass
Spec methodologies to characterize hinge region degradation pathway. Coordinated
dialysis, and outside contractor AAA analysis. Monoclonal Antibody Analytical
development and qualification for GMP use in support of Phase I and II Clinical
Studies
6/2005-ending 10/20/05 Chiron (Biopharma) Berkeley, CA. :
Analytical Development Protein Structure and Analysis Group (Contract/Temp):
Recombinant Proteins
MALDI: introduced and developed protein purification methodology for detergent
removal and characterization of interleukin (IL-2) biotinylation. MALDI mass
determinations for intact and deglycosylated proteins (anti-HIV), peptide mapping of
proteins. Improved protein deglycosylation, digestion, and subsequent SEC
purification. HPLC/mass spectrometry (ESI) Software (Mass Lynx, Protein Lynx, and
Gpmaw) used for sequence verification. Empower for (HPLC) reverse phase HPLC
method set up. Assisted with PAGE (electrophoresis) GMP assay validation for intact
cell lysate quantification of protein of interest.
4/2003–11/2004 Trellis Biosciences, South San Francisco, CA.
Senior Research Assoc / Scientist
Designed and conducted experiments in the development of fluorescent nanobead –
antibody protein conjugation chemistry for cytokine identification and localization
(Intracellular and Cell Surface Staining projects).
Evaluated several combinations of modified styrene surfaces and modified target
functional groups for direct and indirect coupling after oxidative or reductive
4. EricWalters 510-432-2529 pixels3d2003@yahoo.com25200 CarlosBee#199 ,Hayward,Ca 94542
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chemistry. Conventional and bead ELISA development.
Testing of proprietary software developed for digital imaging and quantification of
multihued fluorescent nano-particles
Evaluated methods to improve biocompatibility of nanobeads involving covalent
coupling of hydrophilic surfaces
3/2000–12/2002 Zyomyx, Inc., Hayward, CA.
Senior Research Associate/Associate Scientist
Performed experiments in the development of protein biochips.
Contributed significant improvements in assay development and process development
for cytokine micro array biochip
Improved sensitivity of cytokine assay fourfold (4X)
Developed novel methods to stabilize tethered proteases on microchip surfaces (for
screening Peptides)
1999–1999 Oread, Inc. Palo Alto, CA.
Chemist II
Evaluated pharmaceuticals for dissolution, particle size and purity using HPLC and
particle sizer in accordance with GMP and SOP
1991–1998 Sandoz/Novartis, Inc Palo Alto, CA.
Biochemist II (proteins, metabolites) 8 years experience
Published first native protein purification (enzyme) and kinetic characterization of
Adenylosuccinate synthetase and Inhibition by Phosphohydantocidin in plants
Characterized mechanism of Inhibition of Enzymes by small molecules from libraries
and synthesis by in-house chemists
Purified to homogeneity and kinetically characterized various Proteins from crude
native source materials and recombinant sources
Developed and worked with numerous spectrophotometric, fluorimetric, colorimetric
and HPLC enzyme assays
Designed multiple enzyme pathway assays, including substrate synthesis, both
chemical and enzymatic (see patent)
Implemented, developed, and defended (in scientific project meetings) a biochemical
target site involving several enzymes in a biosynthetic pathway. From literature search
to design of required enzyme assays and substrate synthesis (in collaboration with the
chemistry department). Sought out collaborators and justified creation of the new
project involving multiple departments.
Developed numerous HPLC methods for enzyme assay and metabolite assay (RP,
HIC, Ion exchange/pairing).
5. EricWalters 510-432-2529 pixels3d2003@yahoo.com25200 CarlosBee#199 ,Hayward,Ca 94542
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1988–1991 Beckman Instruments Palo Alto, CA
Senior Applications Scientist
Developed new ELISA applications for robotic laboratory workstations (Biomek and
GenELISA)
Provided Tech support for robotic workstation-software/hardware, both telephone
and in customer laboratories
Wrote technical publications for robotic workstation
Partnered with the Marketing, Sales, Engineering, and Software departments to
develop new uses for the laboratory robotics
Delivered presentations to university and commercial laboratories on the use of the
robotics systems
Worked with Engineering and Software departments to troubleshoot (alpha and beta
testing) new software and hardware, and to develop new attachments, accessories for
the robotic workstation
1985–1988 Cooper Biomedical, Mountain View, CA
Research Assoc I, II, III (Process Development)
Assisted in development of protein purification schemes, analyzed fractions with
ELISA
Trained/ assisted production purification team in scale up in pilot plant
Performed small batch protein (1L) production experiments and scale up to 100L
Performed QC for recombinant protein pilot plant lots
EDUCATION 1984 University of California Santa Cruz, CA
Bachelors in Biochemistry and Molecular Biology
6. EricWalters 510-432-2529 pixels3d2003@yahoo.com25200 CarlosBee#199 ,Hayward,Ca 94542
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PUBLICATIONS
Eric W. Walters, Shy-Fu Lee, Thierry Niderman, Paul Bernasconi, Mani V.
Subramanian, and Daniel L. Siehl Adenylosuccinate Synthetase from Maize,
Purification, Properties, and Mechanism of Inhibition by 5’-Phosphohydantocidin,
Plant Physiol. (1997) 114:549-555
Paul Bernasconi, Eric W. Walters, Alison R. Woodworth, Daniel L. Siehl, Tracey E.
Stone, and Mani V. Subramanian Functional Expression of Arabidopsis thaliana
Anthranilate Synthase Subunit 1 in Escherichia coli, Plant Physiol. (1994)106: 353-
358
Daniel L. Siehl, Mani V. Subramanian, Eric W. Walters, Shy-Fu Lee, Richard J.
Anderson, and Ann G. Toschi Adenylosuccinate Synthetase: Site of Action of
Hydantocidin, a Microbial Phytotoxin Plant Physiol. (1996) 110: 753-758
Daniel L. Siehl, Mani V. Subramanian, Eric W. Walters, Jonathan H. Blanding, Thierry
Niderman, Christian Weinmann Evaluating anthranilate synthase as a herbicide
target Weed Science, 45: 628-633. 1997
Sandra Brunn, Mani V. Subramanian, Eric Walters, Bhavesh Patel, Jeffrey Reagan
Biochemical Characterization of Auxin Transport Protein Using Phytotropins ACS
Symposium Series 557, Bioregulators for Crop Protection and Pest Control, Paul
Hedin, Editor, 202-211, 1994
The Automation of Three Clinically Important ELISAs With The GenELISA™ V2.1
System, Eric Walters, Senior Applications Chemist, Beckman Instruments, Inc.,
Fullerton, CA 92634 Beckman Product Number T-1709-ROB-91-5
Poster: Development and Qualification of an HPLC Oxidation Assay for Botulinum
Neurotoxin Serotype A Antibody Mixture Erica Cleary, Eric Walters, Rahima
Danishmand, Glen Teshima, Vafa Lahidji, Joel Freeberg, and Milan Tomic, XOMA
(US) LLC, 2910 Seventh Street, Berkeley, CA 94710
Poster: Development of Quantitative EBV gp 350 HPLC Assay for Cell Line
Development : Eric Walters*, Ramarao Vepechedu, Medimmune, CCPD, Cell Culture
Development, Santa Clara, CA
POSTER
PATENT
Methods to Screen Herbicidal Compounds Utilizing AIR Synthetase from
Arabidopsis thaliana Eric Ward, David Guyer, Sharon Potter, Venketeswaran
Subramanian, Eric Walters W099/67402 June 22, 1999