Carrier protein

Multi cyclofolded transmembrane proteins

Collection

zero Useful+1

zero

Carrier protein is also called carrier Permeating enzyme (permease) or transporter. Be able to communicate with Specificity Solute binding by itself conformation And transfer the solute bound to it to the other side of the membrane

Carrier protein is a multi cyclofolded transmembrane protein that specifically binds to the transferred molecule to make it cross plasma membrane 。 Its mechanism is carrier protein Molecular conformation Reversibly, the affinity with the transported molecule changes and the molecule is transferred.

The carrier protein needs to combine with the transported ions and molecules, and then complete through its own configuration change or movement material Transported Membrane protein 。 Carrier protein Promote proliferation It also has high specificity, and there are binding points on it. It can only temporarily and reversibly bind and separate with a certain substance. Moreover, a specific carrier only transports one type of chemical substance, or even one molecule or ion.

Carrier proteins are involved in both passive and active material transport. Passive substance transport by carrier protein is not required ATP Provide energy. The transport process of carrier protein to substances has a kinetic curve similar to that of enzyme and substrate, and can be used as analogues Competitive inhibition It has the characteristics of competitive inhibition and other enzymes. However, unlike enzymes, carrier proteins do not do anything to transport molecules Covalent modification 。

Some carrier proteins need energy to drive, such as various ATP driven Ion pump ； Some do not need energy to Free diffusion It is a kind of permission and help to transport the material carrier Water solubility Material penetrates and passes through cell membrane Of lipid Layer and transferred to cells.

Chinese name: Carrier protein
Foreign name: carrier protein
Discipline: biology

Field: cytology
Carrier: sugar amino acid nucleotide Isowater-soluble water molecule
Characteristics: Specificity

catalog

one Action process
two Features

Action process

Announce

edit

Carrier protein and ions on one side of the membrane Specificity To form an unstable carrier ion complex, and then release ions from the other side of the membrane, while the carrier returns to the original side. Certain protein , which can make certain ions pass through. For example, use Artificial membrane When conducting experiments, in general, Potassium ion Can't pass through the artificial from the side with high concentration lipid Bilayer membrane（ Phospholipid bilayer ）, diffuse to the side of low concentration. However, if a small amount of valinomycin (an antibiotic) is added to the lipid bilayer membrane, potassium ions can pass through, while other ions cannot. This is because Valamycin It has specific affinity with potassium ion, and protein structure There are channels suitable for the ion inside. cell membrane This protein is called Ionic carrier 。 Valamycin is the potassium ion carrier. glucose get into red blood cell The reason is that there is a protein on the red blood cell, which has a specific affinity with the transported substance glucose. When this protein combines with glucose, it causes its conformational change, so that glucose enters the cell through the cell membrane.^[1]

Carrier protein

Sugar amino acid ， nucleotide etc. Water solubility Small molecule Generally, it is carried by carrier protein. In a few cases, the carrier may rotate 180 ° with the complex of the transported molecule, thus sending the molecule to the other side of the membrane.

Features

Announce

edit

The kinetic curve of carrier protein transporting substances has "membrane" Conjugating enzyme ”Characteristics of, Transportation speed It reaches saturation at a certain concentration. But the carrier protein is not an enzyme, and it is not Covalent In addition, it not only speeds up transportation, but also increases the permeability of substances plasma membrane Amount of. The carrier protein is specific to the carrier molecule binding site , can be Competitive inhibition Thing occupation competitiveness The inhibitor can also bind to the carrier protein outside the binding site, changing its conformation , blocking transportation. In addition, the carrier protein also has a certain pH dependent effect.

The transport of carrier protein has Specificity And saturation, specificity means that a carrier protein can only transport the only one or a class of substances with very similar properties when transporting substances inside and outside cells; Saturation index cell membrane The number of carrier proteins on the Transportation process When all carrier proteins have undertaken corresponding transportation tasks, the speed of transportation will not be accelerated due to other conditions.

Novice on the road

Growth task Getting Started with Editing Edit Rule Edit by myself

I have questions

Content query Online Service Official post bar Feedback

Complaints and suggestions

Report bad information Failed to appeal through entries Complaint of infringement information Blocking query and unblocking

Jinggong Network Anbei No. 1100000200001