The other major gluten protein type is called glutenin.
Prolamines are used for plant energy storage in the seed.
Each plant species that contains prolamin has a different type. Here are some examples of different prolamin proteins found in various plants:
Not all prolamins trigger celiac disease. There is universal agreement that gliadin, hordein and secalin (from wheat, barley and rye respectively) are major celiac triggers. Avenin (from oats) is considered a trigger by some but not by others. Oats are not particularly high in avenin compared to the amount of gliadin found in wheat. I suggest avoiding oats if you are celiac, and using your own judgment based on how you feel if you have a gluten allergy.
The zein found in corn does not appear to trigger celiac disease. However, some celiacs find that they feel better when they avoid corn. It is possible that zein is the culprit, although this is speculation.
The kafirin found in sorghum appears safe.