Abstract:
:The crowded environment of cells poses a challenge for rapid protein-protein association. Yet, it has been established that the rates of association are similar in crowded and in dilute solutions. Here we probe the pathway leading to fast association between TEM1 β-lactamase and its inhibitor protein BLIP in crowded solutions. We show that the affinity of the encounter complex, the rate of final complex formation, and the structure of the transition state are similar in crowded solutions and in buffer. The experimental results were reproduced by calculations based on the transient-complex theory for protein association. Both experiments and calculations suggest that while crowding agents decrease the diffusion constant of the associating proteins, they also induce an effective excluded-volume attraction between them. The combination of the two opposing effects thus results in nearly identical overall association rates in diluted and crowded solutions.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Phillip Y,Harel M,Khait R,Qin S,Zhou HX,Schreiber Gdoi
10.1016/j.bpj.2012.08.009subject
Has Abstractpub_date
2012-09-05 00:00:00pages
1011-9issue
5eissn
0006-3495issn
1542-0086pii
S0006-3495(12)00870-3journal_volume
103pub_type
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