Protein Scientist, Assistant Director or Associate Director

Protein Scientist, Assistant Director or Associate Director

Job Category: Research - Ionis

Requisition Number: IONIS
004044

• Posted:
  July 2, 2026
• Full-Time

Showing 1 location

Headquartered in Carlsbad, California, with offices in Boston, Massachusetts, and Dublin, Ireland.

We are seeking a highly motivated protein scientist for an Assistant Director or Associate Director role to lead and advance protein discovery and production efforts supporting protein-oligonucleotide conjugate programs. This role will focus on adapting ligands emerging from primary screens into robust, scalable protein fusion formats suitable for downstream characterization, development, and larger-scale production.

The successful candidate will bring deep expertise in protein engineering, molecular design, and recombinant protein production across both microbial and mammalian expression systems. They will be expected to drive the progression of candidate ligands from early discovery into manufacturable protein fusion constructs for conjugation to oligonucleotides, while partnering closely with discovery, chemistry, analytical, and development teams. The ideal candidate is a creative and rigorous scientist who combines strong hands‑on technical depth with strategic thinking.

This role will be central to building a bridge between early ligand discovery and scalable production of protein fusion molecules suitable for protein‑oligonucleotide conjugate applications. The individual in this position will help define candidate quality, establish developable construct formats, and enable the progression of promising ligands into broader therapeutic evaluation.

• Lead design, engineering, expression, purification, and characterization of protein ligands and protein fusion constructs intended for protein‑oligonucleotide conjugates.
• Translate hits from primary screening campaigns into optimized lead molecules with improved expression, stability, manufacturability, and functional performance.
• Develop and execute protein production strategies, selecting fit‑for‑purpose platforms based on construct requirements and downstream use.
• Design fusion proteins and other engineered constructs suitable for scale‑up and conjugation workflows.
• Oversee purification and analytical characterization of recombinant proteins, including assessment of integrity, aggregation, binding, and stability.
• Work closely with oligonucleotide chemistry and conjugation teams to ensure protein constructs are compatible with conjugation requirements and downstream process needs.
• Drive experimental strategy, data interpretation, and decision‑making across multiple programs.
• Mentor scientists and research associates as appropriate and contribute to building scientific capability in protein engineering and production.
• Present results and recommendations clearly to cross‑functional teams and senior leadership.
• Hands‑on laboratory–based effort will be expected.

• PhD in protein science, biochemistry, molecular biology, chemical biology, bioengineering, or related discipline, with relevant industry experience.
• For the Assistant Director position, at least 5 years of relevant industry experience.
• For the Associate Director position, at least 8 years of relevant experience.
• Significant hands‑on experience in recombinant protein expression and purification in both microbial and mammalian systems.
• Demonstrated expertise in protein engineering and design, including construct optimization for expression, stability, and function.
• Strong track record of advancing protein molecules from early discovery or screening through lead optimization and scale‑up.
• Experience generating and evaluating protein fusions or other complex engineered protein formats.
• Experience with analytical methods used for protein characterization.
• Strong scientific judgment, experimental rigor, and problem‑solving ability in a fast‑moving research environment.
• Excellent written and verbal communication skills and ability to work effectively across disciplines.
• Excellent track record of publications.
• Ability to manage multiple assignments effectively in a quickly evolving environment.
• An…