Impact of Tryptophan Oxidation in Complementarity-Determining Regions of Two Monoclonal Antibodies on Structure-Function Characterized by Hydrogen-Deuterium Exchange Mass Spectrometry and Surface Plasmon Resonance

This work is licensed under a Creative Commons Attribution 4.0 International License.Purpose Tryptophan’s (Trp) unique hydrophobic and structural properties make it an important antigen binding motif when positioned in complementarity-determining regions (CDRs) of monoclonal antibodies (mAbs). Oxidation of Trp residues within the CDR can deleteriously impact antigen binding, particularly if the CDR conformation is altered. The goal of this study was to evaluate the conformational and functional impact of Trp oxidation for two mAb subtypes, which is essential in determining the structure-function relationship and establishing appropriate analytical control strategies during protein therapeutics development. Methods Selective Trp oxidation was induced by 2,2′-Azobis(2-amidinopropane) dihydrochloride (AAPH) treatment in the presence of free methionine (Met). The native and chemically oxidized mAbs were characterized by hydrogen-deuterium exchange mass spectrometry (HDX-MS) for conformational changes and surface plasmon resonance (SPR) for antigen-antibody binding. Results Treatment of mAbs with AAPH selectively oxidized solvent accessible Trp residues. Oxidation of Trp within or in proximity of CDRs increased conformational flexibility in variable domains and disrupted antigen binding. Conclusions Trp oxidation in CDRs can adversely impact mAbs’ conformation and antigen binding. Trp oxidation should be carefully evaluated as part of critical quality attribute assessments. Oxidation susceptible Trp should be closely monitored during process development for mAbs to establish appropriate analytical control for manufacturing of drug substance and drug product

Finis Origine Pendet” – Enhancing Later Learning and Professional Socialization Through an Introductory DPT Course

Background and Purpose: In developing a new Doctor of Physical Therapy (DPT) curriculum, the faculty at a mid-west academic health sciences center decided to introduce course content historically placed near the end of the program’s Master of Physical Therapy curriculum at the beginning of the DPT curriculum. The new DPT curriculum was constructed to promote the value of three central themes; 1) evidence-based practice and 2) patient-centered care, both of which contribute to 3) sound clinical decision making. Faculty theorized that by explicitly expressing these themes in a first semester, introductory course, students would acquire a much needed framework for categorizing and integrating future knowledge, and would begin the professional socialization process earlier in the curriculum. The purpose of this report is to describe the new course and provide quantitative and qualitative data regarding the course outcomes.Methods: Quantitative data were gathered via a survey administered to 75 students, 37 who had completed all three years of the program and 38 who had completed the second year of the program. In addition, qualitative data were gathered from first year student essays summarizing the course and describing its influence on their perceptions of the field. Results: More than 80% of second and third year students agreed or strongly agreed that the course had met all of the primary objectives outlined by the faculty. Essays from first year students also supported many of the purposes envisioned in the development of the course. Conclusion: These outcomes suggest students can value and comprehend more advanced content early in allied health curricula and that the early introduction of such content may aid in organizing subsequent learning and professional socialization

Humeral elevation reduces the dynamic control ratio of the shoulder muscles during internal rotation

publisher: Elsevier articletitle: Humeral elevation reduces the dynamic control ratio of the shoulder muscles during internal rotation journaltitle: Journal of Science and Medicine in Sport articlelink: http://dx.doi.org/10.1016/j.jsams.2016.08.026 content_type: article copyright: © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.OBJECTIVES: To determine the differences in the dynamic control ratio of the glenohumeral joint rotators, during internal rotation at 20° and 60° of humeral elevation in the scapular plan. Dynamic control ratio (DCR) is defined as the ratio between eccentric action of the lateral rotators and the concentric action of the medial rotators. DESIGN: A cross-sectional laboratory study. METHODS: Thirty asymptomatic participants (men n=14, women n=16, mean age=29.4±8.9years, BMI: 24.1±5.4) were tested. Peak torque generated by the concentric action of the MR and the eccentric action of the LR of the shoulder joint and the DCR were evaluated on the dominant arm using an isokinetic dynamometer at 20° and 60° of humeral elevation at a speed of 20°/s. RESULTS: There was a significant decrease in the DCR at 60° humeral elevation when compared to 20° humeral elevation (p0.05). CONCLUSIONS: The significant decrease in the DCR as a consequence of a decrease in the eccentric peak torque of the LR when the humerus is in a more elevated position suggests that the introduction of humeral elevation can be used as a progression for improving the eccentric action of the shoulder LR and subsequently the dynamic control of the shoulder