Senior / Principal Scientist, Protein Chemistry (Protein Conjugation & AOCs)

We are a stealth biotechnology company developing precision therapeutics for cardiovascular disease, seeking a highly skilled and hands-on Senior to Principal Scientist to join our Protein Science team.

This role will focus on the design, execution, and optimization of protein–oligonucleotide conjugates (AOCs), including conjugation chemistry, purification, and routine QC/characterization. The successful candidate will be a core technical contributor, working closely with colleagues across Biology and CMC to advance conjugate molecules from early discovery through preclinical development.

This position is ideal for a scientist who thrives at the bench, enjoys solving complex conjugation and characterization challenges, and wants to apply deep expertise to a novel therapeutic modality in a fast-moving biotech environment. The role is expected to deliver discovery-scale conjugates and associated QC data packages to enable functional testing and rapid iteration.

Protein–Oligonucleotide Conjugation & Molecular Design

• Design and execute protein–oligonucleotide conjugation strategies, including linker selection, site-specific conjugation approaches, and reaction optimization.

• Evaluate and optimize conjugation efficiency, heterogeneity, and stability, and drive designs and workflows to improve efficiency, yield, and quality.

• Contribute to the development of AOC architectures optimized for biological performance and manufacturability.

Protein Production, Purification & Characterization

• Purify antibodies, engineered proteins, and conjugates using affinity, ion exchange, and size-exclusion chromatography.

• Perform routine QC to assess conjugation outcomes and purity/heterogeneity (SEC, IEX, CE-SDS, LC-MS)

Protein Engineering Support

• Collaborate on protein and antibody engineering efforts to improve conjugation compatibility, stability, and functional performance.

Cross-Functional Collaboration

• Work closely with Biology and CMC teams to align conjugate design with downstream in vitro and in vivo studies.

• Communicate clearly and proactively on timelines, risks, and data-driven recommendations.

Innovation & Platform Development

• Contribute experimental data and ideas toward advancement of the AOC platform and related intellectual property.

• Develop and document workflows (SOPs), and support method or process transfer as needed (internal or external).

Required:

• Ph.D. in Chemistry, Biochemistry, Chemical Biology, or related field.

• 3-5 years of relevant experience, level-dependent.

• Strong hands-on experience in bioconjugation chemistry, including site-specific conjugation and linker design.

• Proven expertise in protein/antibody purification and conjugation-relevant analytical characterization.

• Experience independently designing experiments and driving technical problems to resolution.

Preferred:

• Prior exposure to AOCs, ADCs, or related bioconjugate modalities.

• Experience with oligonucleotide payload considerations (sequence constraints, structure-function considerations, stability) is a major plus.

• Experience working in early-stage or fast-paced biotech environments.

• Strong experimental rigor and problem-solving skills.

• Ability to operate as a senior individual contributor within a multidisciplinary team.

• Clear communication of complex technical data to scientific colleagues.

• Curiosity, adaptability, and enthusiasm for developing new therapeutic modalities.