This thesis investigates the interaction between GsAF-I, a peptide from the venom of the tarantula Grammostola rosea, and human voltage-gated proton (Hv1) channels, critical in pH regulation and cellular signaling. Utilizing patch clamp techniques on genetically modified Chinese Hamster Ovary cells expressing human Hv1, the study revealed that GsAF-I significantly stabilizes the closed state of these channels, thereby delaying their opening and hastening their closure, with these effects being notably voltage-dependent. The fast onset and reversibility of GsAF-I's actions suggest its potential for therapeutic use, particularly in treating conditions associated with abnormal proton flux, such as cancer and inflammation. These findings underscore the therapeutic promise of tarantula-derived peptides in modulating ion channel activity and contributing to new treatments for diseases involving disrupted proton flux.