With the increasing world population and vegan diet, there has been increasing consumer demand for alternative protein sources. A substitute for animal proteins is the plant protein, for instance, leaves. The Pereskia aculeata, known as ora-pro-nóbis, is undoubtedly a leafy vegetable with great potential due to its relatively high protein content (17 to 28%). This study aimed to produce ora-pro-nóbis protein concentrate (OPNPC) from ora-pro-nóbis leaves flour (OPNF) by isoelectric precipitation at three different pH’s (3.5, 4.0, and 4.5). The protein extraction by precipitation in different pHs produced OPNPC with protein content and extraction yield ranging from 52 to 55% and 1–4%, respectively. Given the highest yield, the concentrate obtained at pH 3.5 (OPNPC3.5) was selected for further investigation and comparison to OPNF. The differences in color, techno-functional properties, in vitro protein digestibility (IVPD), and structural properties were evaluated. Most techno-functional properties were statistically higher in OPNPC3.5 than in OPNF. These included its water solubility, oil holding capacity, foam capacity and stability, and emulsifying activity and stability. OPNPC3.5 had a higher IVPD (80%) than flour (77%). Scanning electron microscopy and Fourier transform infrared spectroscopy confirmed distinct compositions of materials, which can explain the difference in techno-functional properties. The findings indicate controlling protein extraction conditions as a useful technique to maximize the yield of protein concentrate obtained from ora-pro-nóbis, which was more nutritious and had better techno-functional properties than flour. This demonstrates its potential as an alternative plant-based protein to design healthy and sustainable food products.