Instructions: Read the passage below and use the information to answer the subsequent assessment questions. Learning Goal: To become comfortable working with the different types of units commonly encountered in medicinal chemistry. The goal of a drug discovery program is generally to find a molecule that binds a target protein at very low concentrations. As has been mentioned before (in Chapter 2), the binding is normally determined in a biochemical assay, often in the form of a dissociation equilibrium constant (KD). For a drug, the values for KD are very small, indicating the drug and target bind very tightly and do not readily dissociate. Ideal KD values are in the nanomolar (nM) range, but during development observed KD values are much higher. Hits in an early screen might have KD values in the micromolar (µM) range. The table below shows the concentrations regularly encountered in a drug discovery program. name
relation to molarity
moles / liter
millimoles / liter
micromoles / liter
nanomoles / liter
picomoles / liter
Beyond the reporting of binding data (pharmacodynamics), the units in the table above are also found throughout pharmacokinetics, especially in reports of the concentration of drugs in blood. Please complete the online exercise. OPTIONAL‐Please participate in the online discussion forum.
Graphing enzyme kinetics data Background: Interpreting enzyme kinetics data requires one to be able to graph the information. The previous unit contained a video which provided instructions on how to generate graphs from enzyme kinetics data as a saturation plot (Michaelis‐Menten equation) or in linear form (Lineweaver‐Burk equation).