This illustration may be a combination of two images, or simply a program I don't know about. However, there are many protein visualisation programs that can show alpha-helices such as [PyMol][1], [VMD][2] or [Yasara][3]. Here you can ray-trace the image (i.e. transparent background) and then combine the illustration with something else, e.g. an illustration from ChemDraw to produce something like the illustration shown in the question. 


  [1]: https://pymol.org/2/
  [2]: https://www.ks.uiuc.edu/Research/vmd/
  [3]: http://www.yasara.org