Hello and good day to everyone! :)

I have some general questions on crystallography work. I hope you don't mind giving me some ideas. 

I have solved my lipase protein both ground-grown crystals and space-grown crystals with good resolutions (1.4A and 2.2A). They are the same protein from the same source, same purification methods, and produced crystals from the same crystallization conditions (except the gravity part). 

From the data, it shows that both of them belong to the same space group P212121. But they have different number of molecule per asymmetric unit. Ground crystal= 1 molecule/ASU, Space crystal= 2 molecules/ASU. At the moment i have problem explaining this issue. Is it normal to have such results? Same protein with different number of molecule/ASU? 

I've been trying to get some references on this matter but so far i don't really get anything that can directly explain it. Furthermore, do i need to relate this with the gravity effect?

I hope you don't mind sharing some experiences on crystallography especially regarding this matter.

Thank you very much

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FAIROLNIZA

"The advantage of the emotions is that they lead us astray, and the advantage of science is that it is not emotional"
-Oscar Wilde, The Picture of Dorian Gray, 1891