Your browser cookies must be enabled in order to apply for this job. Please contact if you need further instruction on how to do that.

Scientist/Sr. Scientist, Protein Chemistry & Molecular Biology

Protein Chemistry | South San Francisco, CA | Full Time

Job Description

Scientist/Senior Scientist– Protein Chemistry and Molecular Biology


Plexxikon is a leader in the discovery and development of novel, small molecule pharmaceuticals. The company has utilized its proprietary discovery platform to successfully develop a portfolio of competitively differentiated clinical and preclinical stage programs in a number of therapeutic areas. Plexxikon’s most advanced program, Zelboraf® (vemurafenib, and formerly known as PLX4032), was approved by the FDA in 2011 and is approved in over 60 countries worldwide. Plexxikon's demonstrated capability in discovery and early development uniquely positions the company to develop multiple commercial franchises for different therapeutic indications, and create significant value for Plexxikon and its collaborators.

Plexxikon's novel discovery approach, combined with an experienced management and scientific team, a broad network of scientific and clinical experts, and partnerships that support later stage development, have been key drivers of the company's success since it began operations in 2001. In April 2011, Plexxikon became a member of the Daiichi Sankyo Group, and continues to build its broad and diverse pipeline and R&D operations independently.

Plexxikon is a small business with just over 60 employees and this position will be a critical member of the team reporting to the Protein Chemistry & Molecular Biology group leader. This is an exceptional opportunity to gain experience in a successful biotech company.  We are seeking a highly motivated scientist/senior scientist with expertise in protein purification and characterization to join the Protein Chemistry and Molecular Biology group. The candidate will be part of a collaborative team directly contributing to multiple drug discovery programs.


  • Primary responsibilities will reside in the gene to structure process and will be involved in the design, engineering, expression and purification of recombinant proteins from both prokaryotic and eukaryotic (e.g. baculovirus and mammalian) systems
  • Employ protein engineering techniques to optimize soluble protein expression in multiple host systems
  • Expertise in soluble protein expression, protein biochemistry and biophysical characterization.
  • Structural biology experience is a strong plus
  • Establish and optimize growth conditions for the expression of soluble recombinant proteins suitable for crystallographic as well as biochemical activity studies
  • Develop protein purification methods in addition to biochemical/biophysical characterization techniques to support and enable reproducible large-scale protein preps suitable for X-ray crystallography and biochemical assays
  • Support inter-departmental activities necessary for the effective use of protein reagents for assay development, X-ray crystallography, and other drug discovery project needs
  • Provide scientific advice to junior group members and participate in frequent interactions with assay and structural biologists to generate new ideas that will improve our drug discovery process
  • Maintain a current understanding of protein chemistry literature and methodology, as well as other scientific literature related to drug discovery projects
  • Other duties as assigned


  • Ph.D. in an appropriate field (e.g. biochemistry or related discipline) with a focus on protein science, industry experience is a strong plus
  • Experience with various types of protein purification and separation methodologies at laboratory scale is expected
  • Experience with protein design and engineering technologies as applied to improving protein expression/solubility and stability. Additional experience with technologies characterizing protein-small molecule or protein-protein interactions would be a plus
  • Exhibits flexibility and adaptability as projects and goals shift
  • Solid track record of accomplishments; demonstrating technical proficiency, independent thinking and scientific creativity
  • Passionate about drug discovery, with an ability to multi-task while working within a fast-paced and dynamic environment
  • Hands-on, detail and team-oriented, with strong organizational skills
  • Desire to learn and tackle new challenges is imperative 
  • Excellent interpersonal, verbal and written communication skills are essential in this collaborative work environment

Plexxikon, an equal opportunity employer, is located in South San Francisco, just off HW 101.  We offer a chance to work with talented people in a collaborative environment and provide top-notch benefits including health insurance, generous time off, annual performance bonuses, long-term incentives and much more.  If you are interested in applying for this opportunity, please submit your resume or CV, cover letter and salary requirements.  All submissions will be evaluated and interviews will be conducted for those applicants who most strongly fit our needs. If you are not contacted for an interview, your resume will remain on file and active for available positions for a period of one year.

No Phone Calls Please

No Agencies or Recruiters