diff --git a/src/pdb/read_pdb.rs b/src/pdb/read_pdb.rs
index 888441ada62dbc00f1028e8f40aa8c527e472fc2..9069160cb56df4e7374cf882e84f3f5e71793cfd 100644
--- a/src/pdb/read_pdb.rs
+++ b/src/pdb/read_pdb.rs
@@ -138,15 +138,4 @@ pub fn parse_pdb(pdb: &str, name: &str) -> Protein {
     }
     protein
 }
-/// Test if the selected line is a residue
-///
-fn is_protein_res(r: &str, lst: &[&str]) -> bool {
-    let r = r.to_uppercase();
 
-    for res in lst {
-        if r == *res {
-            return true;
-        }
-    }
-    false
-}