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Temperature- and pH-induced multiple partially unfolded states of recombinant human interferon-alpha2a: possible implications in protein stability

, : Temperature- and pH-induced multiple partially unfolded states of recombinant human interferon-alpha2a: possible implications in protein stability. Pharmaceutical Research 20(11): 1721-1729

Purpose: To study the effect of solution conditions on the structural conformation of recombinant human interferon-alpha2a (IFNalpha2a) to investigate its tendency to form partially unfolded intermediates. Methods: The structural properties of IFNalpha2a were studied at various pH values (2.0-7.4) and temperatures (5degreeC-80degreeC) using Trp fluorescence emission, fluorescence quenching, near- and far-UV circular dichroism (CD) spectroscopy, and DSC. Results: Fluorescence intensity measurements as a function of temperature indicated the onset of the thermal unfolding of IFNalpha2a, denoted by Td, around 60degreeC above pH 4.0. Td was not observed at pH 3.5 and below. Acrylamide and iodide quenching studies indicated partial unfolding of protein with decrease in pH and with increase in temperature up to 50degreeC. Near-UV CD studies indicated a significant loss in the tertiary structure of protein on increase in temperature from 15degreeC to 50degreeC at all solution pHs. DSC scans supported results obtained from fluorescence and CD studies at pH 4.0 and below. DSC, however, was insensitive to changes that occurred at moderate temperatures at pH 5.0 and 7.4. Conclusions: IFNalpha2a has a tendency to acquire multiple partially unfolded states with structural conformations sensitive to solution pH and temperature. These states were formed at moderate temperatures, and it is speculated that these partially unfolded states could play an important role in the aggregation of proteins during the long-term storage of aqueous protein formulations.


PMID: 14661914

Other references

Mackenzie, J.R., 1970: Carriage of oxygen equipment by physicians. Canadian Medical Association Journal 102(5): 528-528

Izumi, R.; Niihori, T.; Suzuki, N.; Sasahara, Y.; Rikiishi, T.; Nishiyama, A.; Nishiyama, S.; Endo, K.; Kato, M.; Warita, H.; Konno, H.; Takahashi, T.; Tateyama, M.; Nagashima, T.; Funayama, R.; Nakayama, K.; Kure, S.; Matsubara, Y.; Aoki, Y.; Aoki, M., 2015: GNE myopathy associated with congenital thrombocytopenia: a report of two siblings. GNE myopathy is an autosomal recessive muscular disorder caused by mutations in the gene encoding the key enzyme in sialic acid biosynthesis, UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE/MNK). Here, we report two siblings wi...

Ahmad, N., 1944: Technological reports on trade varieties of Indian cottons, 1944. The results are presented of the 1944 spinning tests on samples of 31 representative commercial varieties of Indian cotton, and three varieties of African cotton, A. R; Kampala, A. R. Busoga and A. R. Jinja. The introduction includes a survey of t...

Smith, H.Q.; Somerville, R.L., 1997: The tpl promoter of Citrobacter freundii is activated by the TyrR protein. The ability of microorganisms to degrade L-tyrosine to phenol, pyruvate, and ammonia is catalyzed by the inducible enzyme L-tyrosine phenol lyase (EC To investigate possible mechanisms for how the synthesis of this enzyme is regulated,...

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Lutz, R.; Lozinski, T.; Ellinger, T.; Bujard, H., 2001: Dissecting the functional program of Escherichia coli promoters: the combined mode of action of Lac repressor and AraC activator. The mode of action of regulated promoters is largely determined by kinetic parameters which govern the interaction between promoters and proteins involved in induction and repression of transcription. To gain insight into the interplay between pos...

Mackay, M., 1991: The Cartwright report. New Zealand Medical Journal 104(908): 125-125

Fabry, S.; Hensel, R., 1988: Primary structure of glyceraldehyde-3-phosphate dehydrogenase deduced from the nucleotide sequence of the thermophilic archaebacterium Methanothermus fervidus. The gene for the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from the thermophilic methanogenic archaebacterium Methanothermus fervidus (growth optimum at 84 degrees C) was cloned in Escherichia coli and the nucleotide seque...

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Asnin, D.I., 1957: Intracutaneous immunotherapy of actinomycosis of head, tongue and neck with actinolysate. Sovetskaia Meditsina 21(3): 51-56