The mechanism of covalent inhibition of LAR phosphatase by illudalic acid.

Leukocyte antigen-related (LAR) phosphatase is a receptor-type protein tyrosine phosphatase involved in cellular signaling and associated with human disease including cancer and metabolic disorders. Selective inhibition of LAR phosphatase activity by well characterized and well validated small molecules would provide key insights into the roles of LAR phosphatase in health and disease, but identifying selective inhibitors of LAR phosphatase activity has been challenging. Recently, we described potent and selective inhibition of LAR phosphatase activity by the fungal natural product illudalic acid. Here we provide a detailed biochemical characterization of the adduct formed between LAR phosphatase and illudalic acid. A mass spectrometric analysis indicates that two cysteine residues are covalently labeled by illudalic acid and a related analog. Mutational analysis supports the hypothesis that inhibition of LAR phosphatase activity is due primarily to the adduct with the catalytic cysteine residue. A computational study suggests potential interactions between the illudalic acid moiety and the enzyme active site. Taken together, these data offer novel insights into the mechanism of inhibition of LAR phosphatase activity by illudalic acid.

Structure of the Cdc48 segregase in the act of unfolding an authentic substrate.

The cellular machine Cdc48 functions in multiple biological pathways by segregating its protein substrates from a variety of stable environments such as organelles or multi-subunit complexes. Despite extensive studies, the mechanism of Cdc48 has remained obscure, and its reported structures are inconsistent with models of substrate translocation proposed for other AAA+ ATPases (adenosine triphosphatases). Here, we report a 3.7-angstrom-resolution structure of Cdc48 in complex with an adaptor protein and a native substrate. Cdc48 engages substrate by adopting a helical configuration of substrate-binding residues that extends through the central pore of both of the ATPase rings. These findings indicate a unified hand-over-hand mechanism of protein translocation by Cdc48 and other AAA+ ATPases.

Measuring primary care organizational capacity for diabetes care coordination: the Diabetes Care Coordination Readiness Assessment.

BACKGROUND: Not all primary care clinics are prepared to implement care coordination services for chronic conditions, such as diabetes. Understanding true capacity to coordinate care is an important first-step toward establishing effective and efficient care coordination. Yet, we could identify no diabetes-specific instruments to systematically assess readiness and/or status of primary care clinics to engage in diabetes care coordination. OBJECTIVE: This report describes the development and initial validation of the Diabetes Care Coordination Readiness Assessment (DCCRA), which is intended to measure primary care clinic readiness to coordinate care for adult patients with diabetes. DESIGN: The instrument was developed through iterative item generation within a framework of five domains of care coordination: Organizational Capacity, Care Coordination, Clinical Management, Quality Improvement, and Technical Infrastructure. PARTICIPANTS: Validation data was collected on 39 primary care clinics. MAIN MEASURES: Content validity, inter-rater reliability, internal consistency, and construct validity of the 49-item instrument were assessed. KEY RESULTS: Inter-rater agreement indices per item ranged from 0.50 to 1.0. Cronbach's alpha of the entire instrument was 0.964, and for the five domain scales ranged from 0.688 to 0.961. Clinics with existing care coordinators were rated as more ready to support care coordination than clinics without care coordinators for the entire DCCRA and for each domain, supporting construct validity. CONCLUSIONS: As providers increasingly attempt to adopt patient-centered approaches, introduction of the DCCRA is timely and appropriate for assisting clinics with identifying gaps in provision of care coordination services. The DCCRA's strengths include promising psychometric properties. A valid measure of diabetes care coordination readiness should be useful in diabetes program evaluation, assistance with quality improvement initiatives, and measurement of patient-centered care in research.

Health services research related to chiropractic: review and recommendations for research prioritization by the chiropractic profession.

PURPOSE: This project updates a previous effort to inventory health services research conducted on chiropractic and makes recommendations for a subsequent research agenda. A qualitative review of social sciences, medical, chiropractic, and health services research literature regarding chiropractic was done with emphasis on research published since the initial health services research agenda effort in 1995. This work informed development of updated health services research recommendations. METHODS: Literature was gathered through searches of electronic health care database retrieval systems and citation tracking. In addition to general collecting of new studies, the authors considered to what extent the 1995 research recommendations had been addressed in the new literature. A seed set of refined recommendations was formulated and initially distributed expert review and revision. The recommendations were made available for public comment and hearing at the 10th Annual Research Agenda Conference for Chiropractic in March 2005. DISCUSSION: The past 10 years have seen numerous health service research studies related to chiropractic; however, nearly all of the research priorities identified in 1995 remain unaddressed and remain as important priorities. Thus, recommendations were reprioritized and revised to submit for open comment and hearing. CONCLUSION: A smaller number of more concise recommendations with more specific action steps are proposed for clinical quality improvement, performing cost analyses, and assessing use barriers for chiropractic.