When proteins are heated above a critical temperature, the higher order structure is lost. Molecular unfolding changes the size of the proteins and exposes otherwise hidden functional groups that can be attracted to similar sites on neighboring molecules. The increase in the attractive component of the protein protein interaction (PPI) can lead to aggregate or cluster formation unless a significant repulsive barrier is present to prevent it.
The electrostatic repulsion can stabilize proteins when in a charged state. To further explore the sensitivity of temperature dependent viscosity measurements to denaturation or melting transition, we have created this application note with a series of dilute BSA solutions in buffers of varying pH. A second part to our initial study of heat (view Part I application note here), download our application note to learn more!
While it is ideal if we could create a general model of melting temperature for every protein, we strongly encourage you to do a wide temperature analysis such as this application note. Each protein could be unique in viscosity at different temperatures.
While there is no one size fits all type of deal when it comes to creating your measurement parameters for your proteins, proteins cannot function properly or will denature when it gets up to the heating temperature of 70 ºC.
When working with RheoSense viscometers, m-VROC and VROC initium, you can use a temperature sweep between 4 - 70 ºC. What this means is that the software will run the temperature control process to various temperatures as instructed in the recipe or protocol.
Lower temperatures tend to be to analyze storage temperature while higher temperatures would be for melting temperature. Please note that you do need to dilute your samples when going to higher temperatures. This will benefit you as you can also run the samples after recovering (with VROC initium) on your HPLC or other lab equipment.