Director, Protein Sciences

About Xaira Therapeutics

Xaira is an innovative biotech startup focused on leveraging AI to transform drug discovery and development. The company leads the development of generative AI models to design protein and antibody therapeutics, enabling the creation of medicines against historically hard‑to‑drug molecular targets. It also develops foundation models for biology and disease to enable better target elucidation and patient stratification. These technologies continually enable identification of novel therapies and improvement in drug development success. Xaira is headquartered in the San Francisco Bay Area, Seattle, and London.

About the Role

As the Director of Protein Sciences, you are the primary architect of the group’s strategic vision. You will autonomously define, prioritize, and execute the protein production and characterization roadmap, proactively driving the protein design team to challenge conventional antibody assumptions and maximize platform innovation while aligning with clinical development objectives.

About You

You are a visionary leader who doesn’t just manage the status quo—you proactively identify bottlenecks and implement innovative solutions to push our protein sciences capabilities forward. You cultivate a culture of scientific rigor, high performance, and rapid iteration, and you build and lead a protein sciences team at the forefront of protein production, characterization, and drug development. You enjoy mentoring and developing team members to develop a passion for drug discovery and novel treatments for patients.

Responsibilities

• Champion and drive cross‑functional integration across diverse research teams—spanning biology, AI design, and engineering—to achieve scientific goals and address complex project demands.
• Push the boundaries of protein science capabilities by evaluating and integrating emerging technologies to increase throughput, data quality, and platform efficiency.
• Direct and optimize protein production from a range of host organisms—E. coli, cell‑free, and mammalian—and a range of throughputs 10 to 1000+ at varying volumes.
• Qualify all recombinant proteins by spectroscopic (UV, fluorescence), electrophoresis (SDS‑PAGE), aggregation (analytical SEC), validated interactions (BLI/SPR), and identity (MS) methods.
• Characterize antibodies for therapeutic properties such as binding kinetics, epitope, stability (thermal and pH), polyspecificity, aggregation propensity, etc.
• Direct purification of soluble and membrane proteins using AKTA and other purification systems.
• Utilize automation systems to ensure efficient and precise execution of experiments.
• Collaborate with Process Development to strategize and perform critical experiments required for clinical development and translate research assays to validated assays for the CMC process.
• Train and mentor junior team members, providing guidance on experimental design, data analysis, and troubleshooting.
• Maintain accurate and detailed records of experiments, protocols, and results in accordance with company standards and regulatory requirements.
• Interpret and present scientific findings at research meetings, providing scientific input and proposing follow‑up experiments.
• Contribute to scientific publications, patents, and presentations to disseminate research findings both internally and externally.

Qualifications

• B.S. or Ph.D. in Structural Biology, Protein Biochemistry, or related fields with 10+ years of industrial experience.
• Deep experience in designing and optimizing antibody production processes, including fermentation, cell culture, and purification.
• Experience using automation to generate high‑throughput (≥1000) small‑scale antibodies and related molecules.
• Hands‑on experience with analytical techniques such as HPLC, Mass Spectrometry, BLI, SPR, ELISA, and CE‑SDS for antibody characterization.
• Ability to analyze experimental data, draw conclusions, and provide insights to inform process optimization.
• Experience working with cross‑functional teams—including research, CMC, and clinical—to ensure alignment and successful product development.
• Maintaining detailed documentation of experimental designs, methods, and results in electronic lab notebooks.
• Contributing to the preparation of technical reports and regulatory documentation.
• Training and mentoring junior team members in protein production and analytical techniques.

Nice to Have

• Background in structural biology (X‑ray crystallography or cryo‑EM) is highly desirable.
• Experience using LIMS and Benchling systems.

Compensation

We offer a competitive compensation and benefits package, including base salary, bonus, and equity. The base pay range for this position is expected to be $196,000–$245,000 annually; the exact offer will vary depending on market, job‑related knowledge, skills and capabilities, and experience.

Equal Employment Opportunity

Xaira Therapeutics is an equal‑opportunity employer. We believe that our strength is in our differences. Our goal to build a diverse and inclusive team began on day one, and it will never end.