March 12, 2018
PhaC is an enzyme that can be used to engineer biodegradable plastics that are more ecologically friendly than their petroleum-based counterparts. Shown here is the catalytic domain from Cupriavidus necator. PDB: 5t6o
March 5, 2018
Escherichia coli (E. coli) bacteria normally live in the intestines of healthy people and animals. Most varieties of E. coli are harmless or cause relatively brief diarrhea. But a few particularly nasty strains, such as E. coli O157:H7, can cause severe abdominal cramps, bloody diarrhea and vomiting. You may be exposed to E. coli from contaminated water or food — especially raw vegetables and undercooked ground beef.
Feb. 26, 2018
In biology, structure determines function. For proteins, this means that proper folding is everything! There is a complicated network of molecules called chaperones which help new proteins fold correctly as they form. One of the most impressive of these molecules is the GroEL/GroES complex. This complex consists of a large barrel made of 14 individual protein units (GroEL), capped by a seven-membered protein lid. When it is uncapped, the GroEL barrel is hydrophobic, and large enough to accommodate proteins up to 60 kilodaltons in size – for reference, the average eukaryotic protein is about ~50kDa in molecular weight, so GroEL can accommodate a wide variety of proteins, large and small. Proteins find their way into this barrel if they are misfolded such that their hydrophobic inside residues are pointed outward and can interact with the hydrophobic barrel walls. When the GroES lid caps GroEL, the misfolded protein is trapped inside, and the inside of the barrel turns hydrophilic. This change creates an isolated environment which favors proper folding and forces the misfolded protein to reorganize itself until its hydrophobic residues are on the inside where they belong!
Feb. 20, 2018
Apolipoproteins are lipid-binding proteins that serve to escort lipids through body and throughout the circulatory system. Atherosclerosis (hardening of the arteries) occurs when the artery wall suffers damage and becomes inflamed. Leukocytes respond to the inflammation and take up lipids (including those bound to apolipoproteins). These become fatty deposits called plaque. Understanding apolipoprotein function is critical to prevention of heart attack and stroke.
Feb. 5, 2018
Plastics are usually made from petroleum-based materials, and there is a push to develop more environmentally friendly biodegradable plastics from natural organic compounds. Polyhydroxybutyrate synthase (PhaC) catalyzes the polymerization of a carbon-rich organic compound that is produced in bacteria, 3-(R)-hydroxybutyryl-coenzyme A. The result of this enzymatic reaction is a biodegradable polymer that can be used for eco-friendly plastics.
Jan. 22, 2018
Bovine Beta-Lactoglobulin is the main protein found in many mammalian milks, including cow's milk. The function of this protein is unknown, but it's ability to bind to hydrophobic molecules suggests a role in transport or combating pathogens. Many of us may be familiar with b-lactoglobulin because, once denatured, it coagulates to form a thin gelatinous film. This is the milk skin that appears when boiling milk for hot chocolate or making cream-based broth. This property has made b-lactoglobulin of interest to the food industry because it can easily be extracted for use elsewhere such as in sport's nutrition drinks. You can find it on the label under its manufactured names of whey concentrate or whey isolate and as hydrolysate or non-hydrolysate. Whey concentrate and isolate are purified forms of b-lactoglobulin while whey hydrolysate is a partially-digested mixture of peptide chains. The idea is that the body will absorb this latter form faster so recovery time is reduced after workouts.
Jan. 15, 2018
The mitochondria are the powerhouse of the cell, and ATP synthase molecules are the generators that drive them. Adenosine triphosphate, usually abbreviated ATP, is often referred to as the "energy currency" of the cell. It provides the fuel for countless cellular reactions. In order to produce ATP, cells metabolize sugars, and use that energy to push hydrogen ions up an “energy hill,” creating a difference in ion concentration across a membrane. Much like how hydroelectric dams use turbines to capture energy from flowing water and turn it into electricity, ATP synthase captures the energy of the ions flowing back “downhill” using a spinning protein rotor. As this rotor moves inside the “turbine”, it provides the energy necessary to create new ATP to power the cell!
Jan. 8, 2018
DNA->RNA->Protein. This progression is called the central dogma of biology. In the first step of this process, DNA is transcribed to messenger RNA molecules that then go on to be translated into proteins that do the work of cell processes. As such, there are many ways to regulate transcription. Proteins involved in the regulation of transcription are called transcription factors. These proteins can upregulate or downregulate how much a gene is expressed. Shown here is the transcription factor CDX2 bound to DNA. PDB: 5LTY
Jan. 1, 2018
Happy New Year from the Macromoltek team! Here is your science fact for the day! Signaling proteins are extremely important for maintaining cells in a healthy state and regulating processes like metabolism and proliferation. In particular, Rab GTPases are master regulators of intracellular trafficking. Since Rab proteins are implicated in multiple aspects of tumour progression including tumour cell migration, invasion, proliferation, communication with stromal cells, and the development of drug resistance. As a consequence, Rab proteins may be novel potential candidates for the development of anticancer drugs.
Dec. 18, 2017
Although we dont yet understand how to effectively cure Parkinson’s disease, a recent breakthrough will hopefully lead to new insights and therapies for the future. Mutations in the PINK1 gene cause early onset Parkinson’s disease. PINK1 is a kinase that, in healthy cells, is processed in the mitochondria and regulates the differentiation of neurons. Recently, a crystal structure was published of PINK1, hopefully resulting in more information to understand the molecular mechanisms of this debilitating disease.