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Article Evaluation

Article - Bioinorganic Chemistry

Content 1. Everything in the article relates to article topic. Something that could be improved would be the specificity of differences between bioinorganic and inorganic chemistry, for example, in order for the reader(s) to better understand the topic and how it differs from similarly named topics. Also, the article could use a few more examples of bioinorganic elements in biology.

Tone 2.There doesn’t show to be any heavy bias throughout the article. The tone within represents the article as a neutral piece of work.

Sources 3. The sources provided with the article are shown to be functional. Multiple references are used for each subsection of the article, and all appropriate citations are provided. Some facts are provided with links to other article pages, as they are referencing supposed common knowledge while further stating their facts. These sources are also shown to be neutral in tone.

Talk Page

4. This article is part of the WikiProject Chemistry, and is shown to have a C-Class rating for quality. Some of the conversations going on involve the debate of changing certain talking points about subsections that could be better served on other similar article pages (overlapping material).

Properties of nickel(II)cyclam perchlorate

 * Molecular formula: C10H24Cl2N4NiO8
 * Molar Mass: 457.915g/mol
 * Melting point (m.p): N/A
 * Boiling point (b.p): N/A
 * Solubility in water: N/A

nickel(II)cyclam perchlorate

nickel(II)cyclam perchlorate

Cyclam

nickel(II)cyclam perchlorate

Assignment topic: Transferrin
The article for Transferrin shows to have a good number of subtopics, but the discussion for each seem too short and provide little information. To further add on to some of the subtopics, I will be focusing on:
 * Structure: further explain the overall composition of the metalloenzyme, as well as include information about the active site(s) present and binding components
 * Activation: add information regarding binding of different substrates to metalloenzyme
 * Medicinal inorganic chemistry: current medical applications of the research on this enzyme, including new research being done. Further add in to present subtopics already present

Note: be sure to actively correct grammar and sentence structure present in article

First 250 word submission
Transferrin is the term used for the group of iron-binding glycoproteins that help with the transportation of Fe(II) atoms within the body's interstitial fluids; distributing iron cells to needed areas while protecting these important ions from possible oxidation at physiological pH levels. Fe(III) ions are more prone to hydrolysis, which leads to the formation of insoluble iron hydroxide compounds, which are toxic within the body and can cause cell damage.

There are multiple differing glycoproteins under the transferrin name, namely lactoferrin (iron-carrying protein present in many bodily fluids including the mucus and milk), ovotransferrin (present in avian egg whites), and serum transferrin. Serum transferrin is typically the protein referred to, as it is present within interstitial fluids such as blood plasma. The overall structure between the types is very similar however: two metal-binding sites for the Fe atoms at the C- and N- terminal domains. An important difference however is the affinities for the Fe atoms between the different types of transferrin.

The transportation of the free Fe atoms is mitigated by the transferrin proteins via a receptor-mediated endocytotic process, where the bound atoms are moved with the proteins, who then transport them to a specified receptor. The receptor recedes into the cell wall, unbinding the Fe atoms from the proteins due to a reaction occuring caused by the differences in pH from external fluid to cell membrane. The iron atoms are now capable to be used where needed, while the protein detaches from the cell wall and goes off to transport other needed Fe atoms.

Fe^3+ reduction and ROS
The key responsibility of transferrin is securely transporting iron atoms to their appropriate locations target sites in the body, without allowing the binded iron to be reduced. This reaction of Fe3+ converted into Fe2+ (in the presence of hydrogen peroxide) is known as the Fenton reaction. Formation of a free radical (hydroperoxyl) is formed as part of the reaction:

Where hydrogen peroxide present in the interstitial fluid interacts with free Fe3+ ions, producing these radicals. Although most free radicals’ damage to cells are mitigated by enzymes such as superoxide dismutase, the high concentration of free radicals is linked to oxidative stress within the cells who effects including inactivation of antioxidant enzymes and the alteration of highly regulated cellular systems.

Transferrin structure
Transferrin is a group of glycoproteins whose structure involves a single polypeptide chain. In humans, transferrin contains 679 amino acids and two carbohydrate chains, while forming two separate lobes with roughly 50% identical sequence identity. These lobes, referenced as the C- and N- lobes, each contain an iron binding site which is found nestled in between the two domains found in each lobe of the protein strand. However, there are notable differences between the two lobes of the proteins, namely the binding strength of the N-lobe being significantly weaker than the C-lobe. The N-lobe is also noted to conform its structure and release its bound iron atom when present in acidic pH at a faster rate than the other lobe.

Bacterial growth
Transferrin proteins' ability to efficiently transport the iron atoms within the organism is also shown to assist in other responsibilities. Iron is a known important element, needed for a lot of important biological processes such as oxygen transportation. It is a limited resource within cells however, as its regulation is needed to retain ideal levels of concentrations to prevent iron-excess and iron anemic environments (both are toxic to cells and can inhibit cellular processes). Iron is also known as an essential nutrient for most bacterial species that infect humans. Over hundreds of years of observations, it had been shown that egg whites (now known as a source of ovotransferrin) could be used to mitigate the spread of infection. We now know this due to the protein's ability to regulation iron concentrations, thus limiting the food source for the bacteria. There have also been studies conducted on the protein lactoferrin and its ability to halt pathogen growth in animal test subjects. When administered exogeneously and compared to subjects that were deficient in lactoferrin, there was less microorganism growth shown in the subjects administered. Although some of these pathogens have come up with mechanisms to overcome the iron-withholding securities like transferrin, such as using metals like manganese as fuel instead of iron like Borrelia burgdorferi.

Transferrin-to-cell cycle
The process of transferrin binding to cells, as well as their specified release and bind operations involves three major techniques used to handle the insolubility of : chelation, reduction and acidification. The process first begins when the protein binds to an appropriate transferrin receptor on the cell surface. The present interstitial is at normal human physiological levels (7.4), which leaves the protein's two iron domains in the closed position. The cell then begins to encapsulate the receptor and bound protein in a vesicle coated in clathrin, a protein used for coating and protecting the complex as it is absorbed into the cellular fluid via endocytosis. At this point, the acidification process begins as the endosome begins to pump protons into the cellular fluid. This ATP-powered process increases the pH of the cell from 6.0 to 5.3. This increase causes the conformation of the protein to change, allowing for the domains carrying the iron atoms to open. The released iron atoms are then reduced from to  via ferrireductase enzymes, and are transported to the cell's cytoplasm by existing DMT-1 transporters for storage or use. The remaining protein-receptor complex, now free of the iron, gets carried back to the cell surface by the vesicle and is released back into the body to carry out its task once again.