affinity

Examples of affinity in the following topics:

• Electron Affinity

  • Mulliken used a list of electron affinities to develop an electronegativity scale for atoms by finding the average of the electron affinity and ionization potential.
  • A molecule or atom that has a more positive electron affinity value is often called an electron acceptor; one with a less positive electron affinity is called an electron donor.
  • To use electron affinities properly, it is essential to keep track of the sign.
  • Electron affinity follows the trend of electronegativity: fluorine (F) has a higher electron affinity than oxygen (O), and so on.
  • This table shows the electron affinities in kJ/mol for the elements in the periodic table.

• Antibodies: Classes and Affinity Maturation

  • Antibodies undergo class switching, somatic hypermutation, and affinity maturation to improve their effectiveness to specific pathogens.
  • Some point mutations result in the production of antibodies having a weaker interaction (low affinity) with their antigen than the original antibody, and some generate antibodies with a stronger interaction (high affinity).
  • B cells that express high affinity antibodies on their surface receive a strong survival signal during interactions with other cells, whereas those with low affinity antibodies do not, and will die by apoptosis.
  • Thus, B cells expressing antibodies with a higher affinity for the antigen outcompete those with weaker affinities for function and survival.
  • The process of generating antibodies with increased binding affinities is called affinity maturation; this occurs in mature B cells after V(D)J recombination and is dependent on help from helper T cells.

• Linear and Quadratic Functions

  • Linear functions may be confused with affine functions.
  • One variable affine functions can be written as $f(x)=mx+b$.
  • Although affine functions make lines when graphed, they do not satisfy the properties of linearity.
  • However, the term "linear function" is quite often loosely used to include affine functions of the form $f(x)=mx+b$.
  • It does not necessarily preserve angles or lengths, but does have the property that sets of parallel lines will remain parallel to each other after an affine transformation.

• Antibody Genes and Diversity

  • This serves to increase the diversity of the antibody pool and impacts the antibody's antigen-binding affinity.
  • Some point mutations will result in the production of antibodies that have a lower affinity with their antigen than the original antibody, and some mutations will generate antibodies with a higher affinity.
  • B cells that express higher affinity antibodies on their surface will receive a strong survival signal during interactions with other cells, whereas those with lower affinity antibodies will not, and will die by apoptosis.
  • Thus, B cells expressing antibodies with a higher affinity for the antigen will outcompete those with weaker affinities for function and survival.
  • The process of generating antibodies with increased binding affinities is called affinity maturation.

• Primary Active Transport

  • With the enzyme oriented towards the interior of the cell, the carrier has a high affinity for sodium ions.
  • The protein's affinity for sodium decreases, and the three sodium ions leave the carrier.
  • The shape change increases the carrier's affinity for potassium ions, and two such ions attach to the protein.
  • The carrier protein, in its new configuration, has a decreased affinity for potassium, and the two ions are released into the cytoplasm.
  • The protein now has a higher affinity for sodium ions, and the process starts again.

• Phosphorus Compounds as Reducing Agents

  • The affinity of trivalent phosphorus for oxygen (and sulfur) has been put to use in many reaction systems, three of which are shown here.

• Antibody Functions

  • In fact, antibodies exhibit different affinities (attraction) depending on the molecular complementarity between antigen and antibody molecules .
  • An antibody with a higher affinity for a particular antigen would bind more strongly and stably.
  • Although avidity measures the strength of binding, just as affinity does, the avidity is not simply the sum of the affinities of the antibodies in a multimeric structure.
  • Typically, multimeric antibodies, such as pentameric IgM, are classified as having lower affinity than monomeric antibodies, but high avidity.

• The Nature of a Family

  • In human context, a family is a group of people affiliated by consanguinity, affinity, or co-residence.
  • In human context, a family is a group of people affiliated by consanguinity, affinity, or co-residence.

• Mapping Protein-Protein Interactions

  • The most widely employed tools are the yeast two-hybrid system and affinity purification coupled to mass spectrometry.
  • Affinity purification of protein complexes coupled to mass spectrometry is carried out as follows: a specific protein (the bait) is manipulated to express an affinity tag.
  • The tag serves as a tool to purify the bait protein and associated proteins by affinity chromatography.

• Iron-Binding Proteins

  • Transferrin has a molecular weight of around 80 KDa and contains two specific high-affinity Fe(III) binding sites.
  • The affinity of transferrin for Fe(III) is extremely high (1023 M−1 at pH 7.4), but decreases progressively with decreasing pH below neutrality.