Tag Info

New answers tagged

5

In biochemistry the Ki is the dissociation constant of a complex and molecules bound to it. It is a measure for the functional strength of the inhibitor. This can for example be an enzyme and its substrate, the Ki defines the stability of the complex. The IC50 on the other hand is the halfmaximal inhibitory concentration of a substance on a biochemical ...


2

Non-engineered IgM (such as is produced in vivo) has the same binding domain on all "arms" of the pentamer. They don't bind to more than one antigen, instead they can bind to multiple copies of the same epitope. Due to steric hindrance, a single IgM molecule generally will not bind at all 10 binding sites.


4

Quoting verbatim from this site. The reference is not really a scientific article but you can check the references it cites. Some were not in English so I did not check. However these points are fairly logical Nitrates are the preferred nitrogen source: Non-volatile: unlike ammonium, nitrate is non-volatile, so there is no need to ...


1

Dihydrouracil oxidase can catalyse the reduction of uracil to dihydrouracil in the presence of hydrogen peroxide. The reduction of uracil to dihydrouracil can also be catalysed by dihydrouracil dehydrogenase using NADH. According to this paper, 5,6-dihydroxycytosine can be formed by treating cytosine or DNA with osmium tetroxide, an extremely strong ...


2

Plants have sulfate transporters which they use to assimilate sulfur. Since sulfate is the conjugate base of sulfuric acid, this could be construed as a "yes" for your question. Sulfuric acid would be present in its conjugate base form at physiological pH values. However, it would be unwise to water your plants with sulfuric acid, as many plants have an ...


1

I opened Lehninger (Principles of biochemistry, 4th ed.) on page 293. The slow Cytosine deamination reaction seems innocuous enough, but is almost certainly the reason why DNA contains thymine rather uracil C is deaminated to U in a rate of 10^-7 in 24 hours, which means 100 mutations a day for a mammalian cell which would have lead to a A-U genome ...


2

One thing that others have not mentioned yet is that the time of the wash can affect the signal. If its washed longer than the usually required 5 minute three time wash, this could result in a reduced (decreased) signal. Reference: http://www.cellsignal.com/common/content/content.jsp?id=western-trouble


1

Additionally to the points in the answer @mattdmo has given, it is possible to enrich the protein of choice before the gel run. This can either be done by using tagged proteins (possibly with the cleavage of the tag before loading) or by doing an immunoprecipitation of your protein. The later is interesting when you have only low concentrations of your ...


2

There are several different places in a typical Western blotting protocol where conditions can be altered to modulate signal intensity. The first is the amount of protein loaded - more protein will give a stronger signal, less will give a weaker signal. However, too much protein can result in indistinct bands, increased background, lane distortion, and other ...


3

There are various mechanisms through which membrane proteins can remain localized in the membrane. See the below figure from MBOTC (book): ...


2

Does it mean that e-NOS and n-NOS are synthesized by mediation of Ca and calmodulin? Calmodulin is activated by binding to calcium and NOS is activated by binding to Ca2+-calmodulin. The binding changes the structural conformation which renders the enzyme active. See this. Are e-NOS and n-NOS expressed on macrophages after induction [...] ...


2

Yes. Freezing would practically stop all biochemical reactions. Household freezer can maintain -15⁰C so that would work. However, freezing also damages the cells if cryoprotectants are not used. But I guess that is not your concern.


3

The following is one of the many elegant statements in General Anesthetic Actions on GABAA Receptors: It is the fervent view of the authors that general anesthesia is no different from any other pharmacological process: exogenously administered drugs interact with key sites on cellular proteins in the body which results directly in the alteration in the ...


3

Clonidine is an agonist on the α2 receptor... but then again norepinephrine is also an agonist on the α2 receptor. Then the physiologic ligand of the a2 receptor, norepinephrine is autocrine (meaning it is released from a cell then binds on a receptor on the same cell) causing negative feed back and it inhibits further release of norepinephrine from the ...


1

I didn't quite understand where you're getting all your OH groups, maybe from the enol tuatomers of the nucleotides. I tried to look up the pKa's for the keto tautomers of the nucleotides on Wikipedia1,2,3,4. In general, if pH is below a functional group's pKa, that group will be protonated, and if pH is above pKa, it will be deprotonated, though this is ...


0

Pretreat the enzyme at high temperature before carrying out the assay at the standard temperature – Alan Boyd


3

All proteins have primary, secondary and tertiary structure. Some have quaternary. Primary structure is the sequence of amino acids. Secondary structure is the local 3D form of a protein. In other words, it is the 3D structure of small regions of protein. This is generally considered to include alpha helices and beta sheets, but often all hydrogen bonds ...


6

Gluten is a protein. The textbook answer is that protein is not stored in fat cells. Proteins are hydrolyzed into amino acids through digestion; some amino acids are ketogenic, and can contribute carbon towards fat biosynthesis. So some of the carbon that originates in gluten may be incorporated into a fatty acid. But the carbon has no 'memory' of its ...


1

How can you differentiate between effects and side-effects of this adrenoblocker in PubChem? I think PubChem will list all sites (receptors) at which a drug reacts, rather than the preferred sites, which I think is appropriate. The pharmacological properties are listed in Section 8: Pharmacology and Biochemistry: Pharmacology Bisoprolol is a ...


3

Lithium changes the effect of at least three substances that play a role in diuresis: aldosterone: lithium partially inhibits its ability to increase the expression of ENaC receptors on apical membrane thus increasing sodium losses [1]. arginine vasopressin (AVP): because lithium can induce hyperparathyroidism, parathyroid hormone can act as partial ...


1

Prokaryotic primases are activated by DNA helicase [1, 2] while the eukaryotic ones are triggered when they form a complex with DNA polymerase alpha and its accessory B subunit [2]. I couldn't find too much information about what exactly triggers activation, but according to De Falco M et al. (2004): [...] synthetic function (of the prokaryotic primase) ...


1

Note: The term equilibrium is different from steady-state w.r.t chemical reactions. Steady state is the right term for the above example. Equilibrium is used in the sense of forward and reverse reactions in a single reversible reaction. The above example considers two irreversible reactions — production and degradation. ... ... the time required for the ...


1

That conversation is strange. While different tables exist, the very first elements seem messed up. If the body is 60 (some sources say 70)% water, then oxygen has to be the most abundant element by weight (water - H2O - has a molecular weight of ~18 g/mol, with hydrogen contributing only 2g/mol of that weight). The usual figures are roughly Oxygen (65%), ...


0

Thiamine(Vitamin B1) deficiency is mostly related to brain diseases, most important task of Thiamine is the conversion of carbohydrates to glucose(food to energy processing)all B complex vitamins are needed for healthy skin,hair,liver,eyes and the proper functioning of nerve system. Thiamine is sometimes called an "anti-stress" vitamin because it may ...


8

Hydrogen peroxide as a reactive oxygen species (ROS) is a highly problematic molecule for the processes inside of cells (it can spontaneously oxidize and damage cellular components). With Catalase, organisms have a very effective enzyme which degrades the peroxide into water and oxygen. However, although the molecule is problematic, it is still produced by ...


8

Actually, there's a lot of animals, plants and microbes can do it. However, it is just an Intermediate process in general. Here's a strong example. In the condition with the absence of catalase, glucose oxidase can catalyze glucose + H2O + O2 become gluconic acid + H2O2. Another process can also generate H2O2 catalyzed by Ero1.


0

This is not a proper answer. Bear with me. I'm in a hurry; will edit the answer to a decent form when I find time. From the abstract of this paper: Of the 80% of oxygen consumption coupled to ATP synthesis, approximately 25-30% is used by protein synthesis, 19-28% by the Na+-K+-ATPase, 4-8% by the Ca2+-ATPase, 2-8% by the actinomyosin ATPase, ...



Top 50 recent answers are included