Possible Random Mechanism in Crystallization Evidenced in Proteins from Plasmodium falciparum

Protein crystallization is a process with considerably indescribable difficulties because many known and unknown factors contribute to the process to varying degrees, which are generally defined as amino acid attributes related to physicochemical properties. However, one might wonder whether randomness plays a role in crystallization. Following this, two questions are (i) can we find out the role of randomness in the crystallization process, and (ii) does more randomness or less randomness in a protein make it easily crystallized? In this study, we used logistic regression and neural network with each of 535 amino acid attributes including randomness attributes to fit the successful rate of crystallization of 118 proteins from Plasmodium falciparum; then we developed a predictive model for checking the role of random attributes in predicting protein crystallization, and we compared crystallized proteins with noncrystallized proteins in terms of random amino acid attributes. The results provide three pieces of clear evidence that randomness plays a role in protein crystallization and a protein that has more randomness is more easily crystallized.