Carbonic anhydrases (CAs) are ubiquitous enzymes that catalyze the reversible hydration/dehydration of carbon dioxide/bicarbonate. As such, there is enormous industrial interest in using CA as a bio-catalyst for carbon sequestration and... more
Carbonic anhydrases (CAs) are ubiquitous enzymes that catalyze the reversible hydration/dehydration of carbon dioxide/bicarbonate. As such, there is enormous industrial interest in using CA as a bio-catalyst for carbon sequestration and biofuel production. However, to ensure cost-effective use of the enzyme under harsh industrial conditions, studies were initiated to produce variants with enhanced thermostability while retaining high solubility and catalytic activity. Kinetic and structural studies were conducted to determine the structural and functional effects of these mutations. X-ray crystallography revealed that a gain in surface hydrogen bonding contributes to stability while retaining proper active site geometry and electrostatics to sustain catalytic efficiency. The kinetic profiles determined under a variety of conditions show that the surface mutations did not negatively impact the carbon dioxide hydration or proton transfer activity of the enzyme. Together these results show that it is possible to enhance the thermal stability of human carbonic anhydrase II by specific replacements of surface hydrophobic residues of the enzyme. In addition, combining these stabilizing mutations with strategic active site changes have resulted in thermostable mutants with desirable kinetic properties.
he extracellular matrix (ECM) corresponds to the extra-cellular component of various multicellular structures such as organisms, tissues and biofilms. The functional role of ECM is to provide structural support and biochemical stability... more
he extracellular matrix (ECM) corresponds to the extra-cellular component of various multicellular structures such as organisms, tissues and biofilms. The functional role of ECM is to provide structural support and biochemical stability to the surrounding cells for cell adhesion, cell-to-cell communication and differentiation. A significant part of the ex-tracellular region is filled by a complex network of proteins and polysaccharides (macromolecules). Such a network is closely attached to the surface of the surrounding cells and forms a spa-tially homogeneous thin film matrix structure. The role of ECM proteins is diverse and critical to maintain the important intracellular signals by providing both mechanical and chemical stimuli to cells. It is possible that various sources of different cell signals may interfere and affect the intracellular sig-nals. Thus, to maintain the integrity of the intracellular signalling pathways, the ability to control the ECM is very important and a ...
Prosthetic implants are routinely employed to treat or replace diseased human bones. The number of hip replacements that take place each year in the United States now ranges between 200,000 and 300,000. It is believed that this number is... more
Prosthetic implants are routinely employed to treat or replace diseased human bones. The number of hip replacements that take place each year in the United States now ranges between 200,000 and 300,000. It is believed that this number is expected to reach 600,000 per year by 2030. Further, the number of knee replacements is expected to reach 3.48 million by 2030 [1]. The replacement of a diseased hip, knee or shoulder can be full or partial. This procedure involves surgical removal of the damaged or diseased parts of the patient's joint and this is followed by replacement with new artificial parts. Such an operation is known as hip, knee or shoulder arthroplasty. The artificial material that replaces the damaged joint is called a prosthesis. Materials that are employed as prosthetic implants are usually made of metal, ceramic, polymer, or various combinations of these materials. In addition to the structural repair that is accomplished by joint replacement, another major purpose...
