Mechanical forces play a crucial role in a myriad of biological processes including numerous diseases and disorders. However, molecular nanobiomechanics are barely considered in modern medicine. There are tens of extracelullar proteins such as integrins, cadherins, selectins, tenascin or talin that withstand mechanical forces that seem to regulate their functions. Most of these proteins have been largely investigated using structural biology techniques such as x-Ray and NMR that have provided a wealth of information. Unfortunately, these techniques cannot reveal how a dynamic mechanical force alters the structure and properties of these proteins. The investigation of the role of mechanical forces in these systems requires the ability to apply mechanical loads to them. This has been possible thanks to the development of single-molecule techniques such as atomic force microscopy (AFM), that allows the application of mechanical forces in the picoscale to individual proteins. This has created an emerging multidisciplinary field, namely mechanobiology, that has atracted the attention of numerous scientists. Our research line focuses on the effect of mechanical forces in proteins and enzymatic reactions that are relevant to our physiology and health. In the past years, we have used AFM techniques for developing methodologies to investigate how force affects the chemistry of enzymes that regulate the redox balance in cells. These enzymes are important in biological processes such as oxidative folding and cell signaling, but also seem to play a role in viral and bacterial infections. In this seminar, I will present our latest research on the nanomechanics of CD4, the primary receptor of HIV-1. Our observations suggest that mechanical forces can trigger structural and chemical alterations in CD4 that might be important during the initial stages of HIV-1 interaction with target cells.