What is cell surface protein?

Cell surface proteins are proteins that are embedded in or span the layer of cell membranes of more complex organisms. These proteins are integral to the way in which a cell interacts with the environment around it, including other cells.

What is the role of surface proteins?

1 Introduction. Cell surface proteins play crucial role in effective communication between the cell and its environment. Around 25–30% of human genes encode for membrane proteins and of these around 3% encode for G protein-coupled receptors (GPCRs) (Vroling et al., 2010; Wallin & von Heijne, 1998).

What are proteins on the surface of the cell membrane called?

Many of these proteins are embedded into the membrane and stick out on both sides; these are called transmembrane proteins. The portions of these proteins that are nested amid the hydrocarbon tails have hydrophobic surface characteristics, and the parts that stick out are hydrophilic (Figure 2).

What are the 3 cell surface proteins?

Based on their structure, there are main three types of membrane proteins: the first one is integral membrane protein that is permanently anchored or part of the membrane, the second type is peripheral membrane protein that is only temporarily attached to the lipid bilayer or to other integral proteins, and the third …

How do you identify surface proteins?

There are two main routes to identify surface proteins. In one approach, membrane and cell wall fractions are separated from the cytoplasmic fraction and then proteins are identified by two-dimensional (2D)-electrophoresis or 2D-chromatography coupled to mass spectrometry [see for example [18-23]].

How many cell surface proteins are there?

Applied to the human proteome, SURFY predicted that the human surfaceome includes 2,886 proteins across all human cell types and developmental stages.

What is the main function of the surface proteins on the surface of a virus?

These proteins mediate two essential functions: attachment of the virion to the cell surface; and fusion of the viral envelope with a cell membrane, resulting in accession of the viral nucleocapsid containing the genome to the cellular cytoplasm.

What are types of surface proteins?

A group of potential surface proteins, that are classified as transmembrane proteases, includes four families: GP36-like metalloproteases, subtilisin-like, serine proteases, and calpain-like cysteine proteases (Kusdian and Gould, 2014).

How do surface proteins attach to the membrane?

The peripheral proteins can attach to the membrane surface by ionic interactions with an integral membrane protein (or another peripheral membrane protein) or by interaction with the polar head groups of the phospholipids.

What are the major types of cell surface proteins and what are their functions?

They are loosely divided into four categories based on their functions: membrane transporters; adhesion molecules and receptors; enzymes; and structural proteins that link the membrane with the membrane skeleton.

How do you identify cell surface receptors?

The presence of cell-surface receptor protein on live cells can be determined by binding assays with labeled ligand or by flow cytometry with labeled antibodies to the receptor. However, non-specific binding is possible even with high-affinity ligands [52].

Is an antigen a cell surface protein?

2. The proteins and glycoproteins that are embedded in the cell membrane provide a distinctive identity to the cell. Since these surface molecules can elicit a response from the immune system, they are cell surface antigens.