Could someone please help with some info?

[Bagrat]

I am looking for my great-grandfather's brother who immigrated to the United States around 1915/1916. My great-grandfather, Sarkis, moved to the Soviet Armenia and had his name changed to Akopov, i assume from Akopian, when registering for passport. However, his brother fled to the US. Both were the only survivors in a fairly large family, members of which were brutally murdered. Unfortunately, not many in my family know much about him other than his last name is either Akopov or Akopian. His brother tried searching for him through Red Cross, without any luck. I tried looking through some online directories and stumbled upon some short list of Armenian immigrants and found someone with a matching last name but incorrect year of birth.
My question for you guys, is whether any of you know some sort of government list of armenian immigrants arriving into the country. Perhaps some other source of relevant information which would help me find his family and children.

Thank you.