PMID- 8868489
OWN - NLM
STAT- MEDLINE
DCOM- 19970304
LR  - 20181113
IS  - 0961-8368 (Print)
IS  - 1469-896X (Electronic)
IS  - 0961-8368 (Linking)
VI  - 5
IP  - 3
DP  - 1996 Mar
TI  - Control of aggregation in protein refolding: the temperature-leap tactic.
PG  - 517-23
AB  - The kinetics of renaturation of bovine carbonic anhydrase II (CAII) were studied 
      from 4 degrees to 36 degrees, at the relatively high [CAII] of 4 mg/mL. Following 
      dilution to 1 M guanidinium chloride, aggregate formation is very rapid and 
      reduces the formation of active enzyme. The CAII activity yield at 150 min, 20 
      degrees (approximately 60%), is greater than that at either 4 degrees or 36 
      degrees. However, if refolding is conducted at 4 degrees, aggregation is reduced 
      dramatically and 37% yield is obtained at 120 min. If the solution is then 
      rapidly warmed to 36 degrees, the yield rises rapidly to 95% at 150 min. This is 
      an example of the "temperature leap" tactic. These results can be understood on 
      the basis of two slow-folding intermediate whose kinetics have been studied. Only 
      the first of these forms aggregates. Kinetic simulations show that, at 4 degrees, 
      the first intermediate is depleted after 120 min, and the second intermediate 
      rapidly isomerizes to active enzyme on warming. A series of experiments was 
      conducted where the initial (120 min) folding temperature was systematically 
      varied, followed by a "leap" to 36 degrees for 30 additional minutes. With 
      initial incubations from 4 degrees to 12 degrees, the final yield is > 90%, drops 
      rapidly from 12 degrees to 20 degrees, and decreases more gradually to 
      approximately 45% at 36 degrees. The overall results qualitatively fit the simple 
      idea of ordinary temperature-accelerated reactions in competition with 
      hydrophobic aggregation, which is strongly suppressed in the cold. Qualifications 
      are discussed for the temperature-leap approach to find application in refolding 
      other proteins.
FAU - Xie, Y
AU  - Xie Y
AD  - Department of Chemistry and Biochemistry, University of Delaware, Newark 19716, 
      USA.
FAU - Wetlaufer, D B
AU  - Wetlaufer DB
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Protein Sci
JT  - Protein science : a publication of the Protein Society
JID - 9211750
RN  - 0 (Guanidines)
RN  - EC 4.2.1.1 (Carbonic Anhydrases)
RN  - JU58VJ6Y3B (Guanidine)
SB  - IM
MH  - Animals
MH  - Carbonic Anhydrases/*chemistry
MH  - Cattle
MH  - Cold Temperature
MH  - Guanidine
MH  - Guanidines/pharmacology
MH  - Kinetics
MH  - Models, Chemical
MH  - Nephelometry and Turbidimetry
MH  - Protein Conformation
MH  - Protein Denaturation
MH  - *Protein Folding
MH  - Temperature
PMC - PMC2143365
EDAT- 1996/03/01 00:00
MHDA- 1996/03/01 00:01
PMCR- 1996/09/01
CRDT- 1996/03/01 00:00
PHST- 1996/03/01 00:00 [pubmed]
PHST- 1996/03/01 00:01 [medline]
PHST- 1996/03/01 00:00 [entrez]
PHST- 1996/09/01 00:00 [pmc-release]
AID - 10.1002/pro.5560050314 [doi]
PST - ppublish
SO  - Protein Sci. 1996 Mar;5(3):517-23. doi: 10.1002/pro.5560050314.