PMID: 19961414Dec 8, 2009

pH-Dependent urea-induced unfolding of stem bromelain: unusual stability against urea at neutral pH

Biochemistry. Biokhimii︠a︡
Basir AhmadRizwan H Khan


Equilibrium unfolding of stem bromelain (SB) with urea as a denaturant has been monitored as a function of pH using circular dichroism and fluorescence emission spectroscopy. Urea-induced denaturation studies at pH 4.5 showed that SB unfolds through a two-state mechanism and yields DeltaG (free energy difference between the fully folded and unfolded forms) of approximately 5.0 kcal/mol and C(m) (midpoint of the unfolding transition) of approximately 6.5 M at 25 degrees C. Very high concentration of urea (9.5 M) provides unusual stability to the protein with no more structural loss and transition to a completely unfolded state.


Apr 1, 1990·Trends in Biotechnology·C N Pace
Feb 15, 1990·The Biochemical Journal·D C WatsonK R Lynn
Jan 1, 1990·Annual Review of Biochemistry·P S Kim, R L Baldwin
May 1, 1989·Biological Chemistry Hoppe-Seyler·A JacquetG Braunitzer
Jan 1, 1986·Gene·L W CohenL C Dihel
Aug 1, 1988·Biological Chemistry Hoppe-Seyler·T DuboisG Braunitzer
Jan 1, 1971·Advances in Protein Chemistry·J DrenthB G Wolthers
Oct 25, 1984·Journal of Molecular Biology·I G KamphuisJ Drenth
Aug 25, 1980·Journal of Molecular Biology·E N Baker
Apr 27, 1995·Biochimica Et Biophysica Acta·A Arroyo-Reyna, A Hernández-Arana
Jun 1, 1997·European Journal of Biochemistry·J M Sanz, G Giménez-Gallego
Nov 2, 1999·Biochemical and Biophysical Research Communications·Suman KunduM V Jagannadham
Jun 23, 2000·Biochimica Et Biophysica Acta·F Edwin, M V Jagannadham
Sep 12, 2000·Journal of Protein Chemistry·Monica SunddM V Jagannadham
Jan 11, 2002·European Journal of Biochemistry·Soghra Khatun HaqRizwan H Khan
Feb 1, 2002·Biochemical and Biophysical Research Communications·F EdwinM V Jagannadham
Feb 20, 2003·Phytochemistry·Vikash Kumar Dubey, M V Jagannadham
May 6, 2003·Archives of Biochemistry and Biophysics·Pawan GuptaM Saleemuddin
Oct 12, 2004·The International Journal of Biochemistry & Cell Biology·Soghra Khatun HaqRizwan H Khan
Oct 14, 2004·Journal of Biochemistry and Molecular Biology·Monica SunddM V Jagannadham

Related Concepts

Stem bromelain
Dayto Anase
Circular Dichroism, Vibrational
Hydrogen-Ion Concentration
Protein Denaturation
Fluorescence Spectroscopy
Stem Cells
Fluorescence Spectroscopy

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Systemic Juvenile Idiopathic Arthritis

Systemic juvenile idiopathic arthritis is a rare rheumatic disease that affects children. Symptoms include joint pain, but also fevers and skin rashes. Here is the latest on this disease.

Chromatin Regulation and Circadian Clocks

The circadian clock plays an important role in regulating transcriptional dynamics through changes in chromatin folding and remodelling. Discover the latest research on Chromatin Regulation and Circadian Clocks here.

Central Pontine Myelinolysis

Central Pontine Myelinolysis is a neurologic disorder caused most frequently by rapid correction of hyponatremia and is characterized by demyelination that affects the central portion of the base of the pons. Here is the latest research on this disease.

Myocardial Stunning

Myocardial stunning is a mechanical dysfunction that persists after reperfusion of previously ischemic tissue in the absence of irreversible damage including myocardial necrosis. Here is the latest research.

Pontocerebellar Hypoplasia

Pontocerebellar hypoplasias are a group of neurodegenerative autosomal recessive disorders with prenatal onset, atrophy or hypoplasia of the cerebellum, hypoplasia of the ventral pons, microcephaly, variable neocortical atrophy and severe mental and motor impairments. Here is the latest research on pontocerebellar hypoplasia.

Cell Atlas Along the Gut-Brain Axis

Profiling cells along the gut-brain axis at the single cell level will provide unique information for each cell type, a three-dimensional map of how cell types work together to form tissues, and insights into how changes in the map underlie health and disease of the GI system and its crosstalk with the brain. Disocver the latest research on single cell analysis of the gut-brain axis here.

Chronic Traumatic Encephalopathy

Chronic Traumatic Encephalopathy (CTE) is a progressive degenerative disease that occurs in individuals that suffer repetitive brain trauma. Discover the latest research on traumatic encephalopathy here.