R01AI155536

Structural Analysis and Inhibitor Optimization of Cryptosporidium N-Myristoyltransferase for Drug Discovery - Abstract

Each year, over 525,000 children under the age of five are killed by diarrhea caused by infectious disease. Cryptosporidiosis, the second most frequent cause of childhood diarrhea, is an infection caused by colonization of the intestines by the eukaryotic parasites Cryptosporidium parvum or C. hominis, and particularly damages and kills malnourished children.

In contrast to other apicomplexans (such as Plasmodium or Toxoplasma), there is no required insect vector or animal host, since parasites can be transferred directly from human to human through the fecal-oral route. Despite the high incidence and significant impact on malnourished children, there are no effective treatments for cryptosporidiosis.

We had previously screened the GSK Tres Cantos proprietary library of ~2 million compounds against P. falciparum N-Myristoyltransferase (NMT). NMT is an enzyme which transfers myristate, a 14-carbon fatty acid, to the N-terminal glycine residue of proteins co-translationally, which contributes to targeting the substrate protein to membrane regions. NMT has been validated as a drug target in fungal and parasitic diseases, including malaria and leishmaniasis.

We hypothesized that NMT high-throughput screening (HTS) hits effective against Plasmodium would also be active against Cryptosporidium and tested the top eight hits against Cryptosporidium parvum NMT (CPNMT). Of those top eight hits, three were effective against the purified enzyme and one showed activity against the parasite in vitro.

A follow-on synthetic chemistry and structure-based drug design program further developed these hits into a lead series (called Series-2) of highly effective (~10nM IC50) inhibitors with 500-1000x selectivity over the human enzyme. The two most promising leads from the Series-2 scaffold were then tested in a mouse model of infection and found that both molecules completely cleared infection.

These data serve to chemically validate NMT as a druggable target for the treatment of cryptosporidiosis. In this proposal, we intend to further develop lead compounds in order to improve drug-like characteristics in preparation for preclinical drug development.

Seattle Children's Hospital

TO ASSIST PUBLIC AND PRIVATE NONPROFIT INSTITUTIONS AND INDIVIDUALS TO ESTABLISH, EXPAND AND IMPROVE BIOMEDICAL RESEARCH AND RESEARCH TRAINING IN INFECTIOUS DISEASES AND RELATED AREAS, TO CONDUCT DEVELOPMENTAL RESEARCH, TO PRODUCE AND TEST RESEARCH MATERIALS. TO ASSIST PUBLIC, PRIVATE AND COMMERCIAL INSTITUTIONS TO CONDUCT DEVELOPMENTAL RESEARCH, TO PRODUCE AND TEST RESEARCH MATERIALS, TO PROVIDE RESEARCH SERVICES AS REQUIRED BY THE AGENCY FOR PROGRAMS IN INFECTIOUS DISEASES, AND CONTROLLING DISEASE CAUSED BY INFECTIOUS OR PARASITIC AGENTS, ALLERGIC AND IMMUNOLOGIC DISEASES AND RELATED AREAS. PROJECTS RANGE FROM STUDIES OF MICROBIAL PHYSIOLOGY AND ANTIGENIC STRUCTURE TO COLLABORATIVE TRIALS OF EXPERIMENTAL DRUGS AND VACCINES, MECHANISMS OF RESISTANCE TO ANTIBIOTICS AS WELL AS RESEARCH DEALING WITH EPIDEMIOLOGICAL OBSERVATIONS IN HOSPITALIZED PATIENTS OR COMMUNITY POPULATIONS AND PROGRESS IN ALLERGIC AND IMMUNOLOGIC DISEASES. BECAUSE OF THIS DUAL FOCUS, THE PROGRAM ENCOMPASSES BOTH BASIC RESEARCH AND CLINICAL RESEARCH. SMALL BUSINESS INNOVATION RESEARCH (SBIR) PROGRAM EXPANDS AND IMPROVES PRIVATE SECTOR PARTICIPATION IN BIOMEDICAL RESEARCH. THE SBIR PROGRAM INTENDS TO INCREASE AND FACILITATE PRIVATE SECTOR COMMERCIALIZATION OF INNOVATIONS DERIVED FROM FEDERAL RESEARCH AND DEVELOPMENT, TO INCREASE SMALL BUSINESS PARTICIPATION IN FEDERAL RESEARCH AND DEVELOPMENT, AND TO FOSTER AND ENCOURAGE PARTICIPATION OF SOCIALLY AND ECONOMICALLY DISADVANTAGED SMALL BUSINESS CONCERNS AND WOMEN-OWNED SMALL BUSINESS CONCERNS IN TECHNOLOGICAL INNOVATION. THE SMALL BUSINESS TECHNOLOGY TRANSFER (STTR) PROGRAM STIMULATES AND FOSTERS SCIENTIFIC AND TECHNOLOGICAL INNOVATION THROUGH COOPERATIVE RESEARCH AND DEVELOPMENT CARRIED OUT BETWEEN SMALL BUSINESS CONCERNS AND RESEARCH INSTITUTIONS, TO FOSTER TECHNOLOGY TRANSFER BETWEEN SMALL BUSINESS CONCERNS AND RESEARCH INSTITUTIONS, TO INCREASE PRIVATE SECTOR COMMERCIALIZATION OF INNOVATIONS DERIVED FROM FEDERAL RESEARCH AND DEVELOPMENT, AND TO FOSTER AND ENCOURAGE PARTICIPATION OF SOCIALLY AND ECONOMICALLY DISADVANTAGED SMALL BUSINESS CONCERNS AND WOMEN-OWNED SMALL BUSINESS CONCERNS IN TECHNOLOGICAL INNOVATION. RESEARCH CAREER DEVELOPMENT AWARDS SUPPORT THE DEVELOPMENT OF SCIENTISTS DURING THE FORMATIVE STAGES OF THEIR CAREERS. INDIVIDUAL NATIONAL RESEARCH SERVICE AWARDS (NRSAS) ARE MADE DIRECTLY TO APPROVE APPLICANTS FOR RESEARCH TRAINING IN SPECIFIED BIOMEDICAL SHORTAGE AREAS. IN ADDITION, INSTITUTIONAL NATIONAL RESEARCH SERVICE AWARDS ARE MADE TO ENABLE INSTITUTIONS TO SELECT AND MAKE AWARDS TO INDIVIDUALS TO RECEIVE TRAINING UNDER THE AEGIS OF THEIR INSTITUTIONAL PROGRAM.

93.855 - Allergy and Infectious Diseases Research

National Institute of Allergy and Infectious Diseases (NIAID) [HHS - NIH]

Seattle, Washington 981095235 United States

Single Zip Code

Research Project Grant (Parent R01 Clinical Trial Not Allowed) (PA-19-056)

Amendment Since initial award the total obligations have increased 389% from $850,984 to $4,163,372.