Senior Research Scientist

Protein Chemist We are seeking a highly motivated and experienced Protein Chemist to join our Structural Biology and Protein Production team within the Protein Science & Technology Department. The successful candidate will play a critical role in accelerating gene-to-structure workflows and antibody discovery programs, integrating expertise in protein engineering, recombinant protein production, biophysical characterization, biologics purification and structural biology. This is a highly collaborative role supporting small-molecule and biologics drug discovery programs. The ideal candidate will bring strong hands-on expertise in protein expression, purification, antibody purification, analytical characterization, and protein quality assessment, with a proven ability to deliver high-quality proteins, antibodies, and protein complexes for downstream applications. The candidate will contribute to multiple programs focused on developing Client therapeutics and enabling technologies designed to accelerate translation of drug discovery programs toward clinical development. The successful candidate will work closely with protein chemists, structural biologists, assay scientists, and other cross-functional partners in a fast-paced, matrixed environment. Summary of Essential Functions Independently design and optimize recombinant protein constructs for expression and downstream applications. Perform transfection of plasmids into mammalian cells, cell line maintenance, generation of baculovirus, and protein expression in insect (Sf9) and mammalian systems. Express recombinant proteins using bacterial expression systems and optimize conditions to maximize yield, solubility, and quality. Develop and execute protein purification workflows using chromatography techniques including affinity, ion-exchange, hydrophobic interaction, and size-exclusion chromatography (SEC). Develop and execute purification strategies for antibodies, antibody fragments, and antibody-containing complexes. Perform antibody purification and QC, including assessment of purity, aggregation, integrity, concentration, and overall sample quality using appropriate analytical methods. Characterize purified proteins and antibodies using a broad range of biochemical and biophysical techniques, including analytical SEC/HPLC, SDS-PAGE, intact-mass analysis where applicable, DSF/thermal shift assays, BLI, SPR, and other analytical assays. Establish and apply protein and antibody quality-control criteria to ensure samples are suitable for structural studies, binding assays, biochemical assays, immunization campaigns, and other downstream applications. Evaluate protein and antibody stability, homogeneity, aggregation state, concentration, and batch-to-batch consistency; identify potential quality issues and implement appropriate corrective strategies. Troubleshoot recombinant protein and antibody expression, purification, and stability challenges to improve yield, purity, monodispersity, and functional quality. Generate high-quality protein samples and protein complexes for X-ray crystallography, cryo-EM, biophysical studies, biochemical assays, and other structural biology applications. Support antibody discovery programs by providing purified and well-characterized antibody molecules and complexes for downstream functional and structural characterization. Independently plan and execute small- and large-scale expression, purification, and characterization experiments while effectively managing multiple projects and priorities. Contribute to the daily operations of a highly productive protein production laboratory, including maintaining equipment, improving workflows, and supporting laboratory development and technology implementation. Analyze and interpret experimental data, communicate results clearly, and make data-driven recommendations that can influence program strategy and decision-making. Collaborate effectively with protein engineers, structural biologists, assay scientists, computational scientists, and project teams in a highly matrixed environment. Contribute to the development and implementation of AI-enabled and technology-driven approaches to accelerate protein production, characterization, structural biology, and drug discovery workflows. Maintain accurate experimental records and communicate results through presentations, written reports, and cross-functional project meetings. Work effectively in a fast-paced, dynamic environment while maintaining high scientific and operational standards. Requirements PhD in Biochemistry, Biophysics, Protein Chemistry, Molecular Biology, Structural Biology, or a related field with at least 2 years of relevant experience, or a Master's degree with at least 5 years of relevant experience in drug discovery, biotechnology, pharmaceutical research, or an academic laboratory. Demonstrated hands-on expertise in protein chemistry, recombinant protein expression, purification, and biophysical characterization. Experience with purification and characterization of antibodies and/or antibody fragments, including development and optimization of purification workflows and analytical QC. Demonstrated experience evaluating protein and antibody purity, homogeneity, aggregation, stability, integrity, and suitability for downstream applications. Proficiency with chromatography-based purification techniques, including affinity, ion exchange, and SEC. Experience with analytical and biophysical techniques such as SEC-HPLC, DSF/thermal stability assays, BLI, SPR. Proven ability to troubleshoot challenging protein expression and purification problems and independently develop effective solutions. Proven experience supporting drug discovery programs through protein chemistry. Ability to independently manage multiple projects, prioritize competing demands, and deliver high-quality results on established timelines. Excellent communication, collaboration, and interpersonal skills. Demonstrated ability to work effectively in cross-functional and matrixed teams. Self-driven, creative, scientifically curious, and entrepreneurial, with the ability to thrive in a fast-paced and evolving research environment. Preferred Qualifications Cryo-EM and/or Crystallography experience is highly desirable but not required. Experience producing and characterizing antibody therapeutics, bispecific antibodies, antibody fragments, or antibody–protein complexes. Experience with antibody purification process development, including Protein A/G capture, polishing strategies, SEC, ion exchange, and aggregate removal. Experience establishing or implementing analytical QC workflows for antibodies and recombinant proteins. Experience with intact-mass spectrometry, SEC-MALS, DLS, capillary electrophoresis, or other advanced protein characterization technologies is desirable. Experience preparing proteins and complexes for cryo-EM and/or X-ray crystallography is highly desirable. Experience with structural biology workflows and interpretation of protein/complex quality requirements for structure determination is highly desirable. Familiarity with protein engineering, construct design, or computational/AI-assisted protein design. Experience working across small-molecule and biologics discovery programs. A strong publication record or established reputation in protein biochemistry, biophysics, protein chemistry, or structural biology is highly desirable. Key Attributes for Success The successful candidate will be a hands-on scientist and collaborative team player who combines strong technical expertise with scientific curiosity and a strong commitment to quality. They will be comfortable moving from construct design and protein expression through purification, antibody QC, biophysical characterization, and delivery of fit-for-purpose samples to downstream teams. The ability to rapidly troubleshoot, communicate effectively across disciplines, and translate experimental results into actionable recommendations will be essential for success in this role. Kaztronix is an equal opportunity employer and does not discriminate on the basis of race, color, national origin, sex, age, religion, disability, veteran status or any other consideration made unlawful by federal, state or local laws. In addition, all human resource actions in such areas as compensation, employee benefits, transfers, layoffs, training and development are to be administered objectively, without regard to race, color, religion, age, sex, national origin, disability, veteran status or any other consideration made unlawful by federal, state or local laws. By applying to the position, you acknowledge that your information will be used by Kaztronix in processing your application. Kaztronix