Marilee Benore-Parsons

Substrate phosphorylation can inhibit proteolysis by trypsin-like enzymes

The effect of substrate phosphorylation on the susceptibility to proteolytic cleavage by trypsin-like enzymes was investigated using the model heptapeptide Leu-Arg-Arg-Ala-Ser-Leu-Gly, a peptide representing the endogenous phosphorylation site of pyruvate kinase. Phosphorylation of Ser 5 altered the kinetics of proteolysis by two proteases, trypsin and rat plasma kallikrein, both of which cleaved between Arg 3 and Ala 4. In the case of trypsin, phosphorylation decreased the rate of cleavage 47-fold. In the case of rat plasma kallikrein, phosphorylation decreased proteolysis 13-fold. Phosphorylation resulted in an apparent redirection of the preferential site from Arg 3 to Arg 2. Because sequences analogous to this model peptide are commonly found in exposed domains of globular proteins, and since these regions are susceptible to both phosphorylation and protease attack, the results indicate that substrate phosphorylation may selectively influence protein processing and turnover.

A curriculum skills matrix for development and assessment of undergraduate biochemistry and molecular biology laboratory programs.

We have designed a skills matrix to be used for developing and assessing undergraduate biochemistry and molecular biology laboratory curricula. We prepared the skills matrix for the Project Kaleidoscope Summer Institute workshop in Snowbird, Utah (July 2001) to help current and developing undergraduate biochemistry and molecular biology program designers to determine which laboratory techniques, skills, and theories to include in a 4‐year plan. The skills matrix can be used to evaluate and assess the types of laboratory skills as well as the level at which they are taught in biochemistry and molecular biology curricula. The matrix can foster better communication between faculty in chemistry, biology, math, and physics as they share curricular information. As an example of utility of the skills matrix, we used it to survey several commonly used biochemistry laboratory manuals to evaluate the skills covered in each text.

Association of Copper to Riboflavin Binding Protein; Characterization by EPR and XAS

The association of copper to Riboflavin Binding Protein (RBP) from egg white has been studied by electron paramagnetic resonance (EPR) and X-ray absorption (XAS) spectroscopies. The type II site contains a mix of copper I and II in an oxygen rich environment.

Investigation of the copper binding site and the role of histidine as a ligand in riboflavin binding protein

Riboflavin Binding Protein (RBP) binds copper in a 1:1 molar ratio, forming a distinct well-ordered type II site. The nature of this site has been examined using X-ray absorption and pulsed electron paramagnetic resonance (EPR) spectroscopies, revealing a four coordinate oxygen/nitrogen rich environment. On the basis of analysis of the Cambridge Structural Database, the average protein bound copper-ligand bond length of 1.96 A, obtained by extended x-ray absorption fine structure (EXAFS), is consistent with four coordinate Cu(I) and Cu(II) models that utilize mixed oxygen and nitrogen ligand distributions. These data suggest a Cu-O 3N coordination state for copper bound to RBP. While pulsed EPR studies including hyperfine sublevel correlation spectroscopy and electron nuclear double resonance show clear spectroscopic evidence for a histidine bound to the copper, inclusion of a histidine in the EXAFS simulation did not lead to any significant improvement in the fit.

A course designed for undergraduate biochemistry students to learn about cultural diversity issues

Biology, biochemistry, and other science students are well trained in science and familiar with how to conduct and evaluate scientific experiments. They are less aware of cultural issues or how these will impact their careers in research, education, or as professional health care workers. A course was developed for advanced undergraduate science majors to learn about diversity issues in a context that would be relevant to them, entitled “Diversity Issues in Health Care: Treatment and Research.” Learning objectives included: developing awareness of current topics concerning diversity issues in health care; learning how research is carried out in health care, including pharmaceutical research, clinical trials, and social research; and learning about health care practices. Lectures and projects included readings on laboratory and clinical research, as well as literature on legal, race, gender, language, age, and income issues in health care research and clinical practice. Exams, papers, and a service learning project were used to determine the final course grade. Assessment indicated student understanding of diversity issues was improved, and the material was relevant.

Teaching Receptor Theory to Biochemistry Undergraduates.

Receptor:ligand interactions account for numerous reactions critical to biochemistry and molecular biology. While students are typically exposed to some examples, such as hemoglobin binding of oxygen and signal transduction pathways, the topic could easily be expanded. Theory and kinetic analysis, types of receptors, and the experimental assay techniques should be included to properly prepare students for careers in research, medicine, or professional programs. In this article we offer a range of material for teaching these concepts to students.