Senior Scientist

Pfizer Worldwide Research & Development, La Jolla, CA Pfizer Worldwide Research and Development in La Jolla, CA is seeking a highly motivated scientist to join the Structural Biology and Protein Sciences (SBPS) Group within the Department of Oncology Medicinal Chemistry. The SBPS mission is to enable oncology drug discovery through expert protein production, biophysical interrogation, and structure-based insight, delivering high quality protein tools and data required to accelerate medicinal chemistry and translational decisions. The position will primarily support the small molecule portfolio, with opportunities to enable emerging targets and novel therapeutic modalities. Role Responsibilities This position is laboratory-based and best suited for an experimental scientist with deep expertise in protein expression, purification, biophysical characterization, and crystallization of challenging targets. The successful candidate for this position will: Work under supervision as a technical expert in the gene-to-structure pipeline, from construct design and expression through advanced purification, biophysical characterization, high-throughput crystallization and orthologous structure enablement including sample and grid preparation to enable cryo-EM. Support multiple small molecule oncology drug discovery programs in parallel. Collaborate with colleagues in Structural Biology and Protein Sciences, Medicinal Chemistry, Biophysics, Enzymology and Computational Chemistry, serving as protein sciences and structural biology resource on multidisciplinary teams and providing clear data, troubleshooting, and high-quality experimental insight to enable rapid decision making. Identify and integrate emerging protein and structural biology technologies to strengthen current capabilities within the group. Required Qualifications B.S., M.S., or Ph.D. (or equivalent) in Biochemistry, Structural Biology, Protein Sciences or a related discipline, with 9+ years of relevant experience for a Bachelor’s degree, 7+ years for a Master’s degree, or 0+ years' experience required for a Ph.D. Extensive hands‑on laboratory experience in advanced protein biochemistry, with a proven track record of producing high‑quality protein samples from exceptionally challenging targets for structural and biophysical studies. Expertise in protein construct design, expression across multiple systems, and complex, multi‑step purification workflows, including development of fit‑for‑purpose proteins to support crystallography, structure‑based drug discovery, biochemical assays and hit identification screens Strong background in biophysical characterization (e.g., stability, oligomeric state, SPR, ITC, BLI) to assess protein quality and guide construct, purification, and ligand strategies. Hands‑on experience in protein crystallization and small‑molecule co‑crystallization, including condition screening, optimization, and crystal improvement. A track record reflecting experimental rigor, creativity, and productivity in protein sciences and structural biology. Ability to thrive in a fast‑paced, highly collaborative, and multi‑project research environment. Excellent communication and interpersonal skills, with commitment to collaborative science, knowledge sharing, and inclusive teamwork. Preferred Qualifications Experience working with various protein classes and multi-protein complexes, including strategies to stabilize and optimize samples for downstream structural, biochemical and biophysical analysis Hands‑on experience with protein purification and crystallization instrumentation, including chromatography systems, crystallization platforms, and automated crystal imaging and screening technologies. Experience with cryo‑electron microscopy workflows including sample optimization and grid preparation Experience applying ML/AI‑enabled approaches to protein engineering, construct design, or structure determination. PHYSICAL/MENTAL REQUIREMENTS Must be able to work safely in a laboratory environment with lab coat, protective eye wear and gloves. The job requires standing, walking for most of the day regular workday with occasional lifting of moderately heavy lab utilities. Candidate may need to use step stools to climb and reach items above eye level. Candidate will also diagnose and repair equipment with various tools occasionally. Work Location Assignment: On Premise The annual base salary for this position ranges from $93,600.00 to $156,000.00. In addition, this position is eligible for participation in Pfizer’s Global Performance Plan with a bonus target of 12.5% of the base salary and eligibility to participate in our share based long term incentive program. We offer comprehensive and generous benefits and programs to help our colleagues lead healthy lives and to support each of life’s moments. Benefits offered include a 401(k) plan with Pfizer Matching Contributions and an additional Pfizer Retirement Savings Contribution, paid vacation, holiday and personal days, paid caregiver/parental and medical leave, and health benefits to include medical, prescription drug, dental and vision coverage. Learn more at Pfizer Candidate Site – U.S. Benefits | (uscandidates.mypfizerbenefits.com). Pfizer compensation structures and benefit packages are aligned based on the location of hire. The United States salary range provided does not apply to Tampa, FL or any location outside of the United States. Relocation assistance may be available based on business needs and/or eligibility. Candidates must be authorized to be employed in the U.S. by any employer. U.S. work visa sponsorship (such as TN, O-1, H-1B, etc.) is not available for this role now or in the future. Sunshine Act Pfizer reports payments and other transfers of value to health care providers as required by federal and state transparency laws and implementing regulations. These laws and regulations require Pfizer to provide government agencies with information such as a health care provider’s name, address and the type of payments or other value received, generally for public disclosure. Subject to further legal review and statutory or regulatory clarification, which Pfizer intends to pursue, reimbursement of recruiting expenses for licensed physicians may constitute a reportable transfer of value under the federal transparency law commonly known as the Sunshine Act. 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This position requires permanent work authorization in the United States. Pfizer endeavors to make accessible to all users. If you would like to contact us regarding the accessibility of our website or need assistance completing the application process and/or interviewing, please email View email address on click.appcast.io. This is to be used solely for accommodation requests with respect to the accessibility of our website, online application process and/or interviewing. Requests for any other reason will not be returned. Research and Development Pfizer careers are like no other. In our culture of individual ownership, we believe in our ability to improve future healthcare, and potential to transform millions of lives. We’re looking for new talent to join our global community, to unearth new innovative therapies that make the world a healthier place.