Cry proteins divided into four main groups or first ranks, viz., Cryl, Cry II, CryIII and CryIV, on the basis of their insecticidal activities.

TLS Online TPP Program

#Id: 9876

#Unit 4. Cell Communication and Cell Signaling

These epithelial barriers include the skin and the tissue surfaces connected to the body’s openings.

Skin and other epithelia provide a kind of living “plastic wrap” that encases and protects the inner domains of the body from infection.

TLS Online TPP Program

#Id: 9877

#Unit 4. Cell Communication and Cell Signaling

Chemical barriers at these surfaces include specialized soluble substances that possess antimicrobial activity as well as acid pH.

TLS Online TPP Program

#Id: 9878

#Unit 4. Cell Communication and Cell Signaling

Antimicrobial proteins

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#Id: 9879

#Unit 4. Cell Communication and Cell Signaling

Antimicrobial peptide

TLS Online TPP Program

#Id: 9880

#Unit 4. Cell Communication and Cell Signaling

Antimicrobial peptides generally are cysteine-rich, cationic, and amphipathic. 

Because of their positive charge and amphipathic nature, they interact with acidic phospholipids in lipid bilayers, forming pores and disrupting the membranes of bacteria, fungi, parasites, and viruses.

TLS Online TPP Program

#Id: 9881

#Unit 4. Cell Communication and Cell Signaling

Defensins and cathelicidin LL-37 are secreted constitutively by epithelial cells in many tissues, and are stored as well in neutrophil granules, where they contribute to killing phagocytosed microbes.