I had a talk with the grandfather. His name is Leonid (79 years old), he had an older brother Boris (died in 1995). Their father's name was Illarion Nikitich Shaporenkov (b. 1888, of Russian descent), and the mother was Ida Efremovna Zhits(b.1889(8?), of Jewish descent). Hi doesn't remember any other names.
My grandfather was born in a village of Zakharyino of Hislavitchi region of Smolensk. I think the following link is a good description of what was going on there:
http://admin.smolensk.ru/history/raion/book/-E-.htm (It's in Russian, but I believe you can read Russian). The grandfather told me that many Jews of Zhits surname have emigrated to US before the World War II, and his mother regularly received US-made goods and letters by mail.