Structural Biochemistry/Proteins/Protein Studies

Protein studies involves various step of sample preparation. The main protocols of protein studies are as followed:

1. Protein Synthesis
2. Purification
3. Evaluation of purified protein
4. Determination of Amino Acid Sequence
5. Calculation of Protein's Mass
6. Determination of Protein's 3-D Structure

There are many methods used to study proteins, including its shape and structure. For instance, X-Ray crystallography is used to give scientists the structure of the protein. Such information is used extensively in determining the characteristics of the protein as well as how it functions and under which circumstances. Other methods used includes amino acid sequencing, fluorescence microscopy, mass spectrometry, NMR, etc.

Carbohydrate-Binding Proteins

Carbohydrate-Binding proteins (CBPs) are identified as important mediators for numerous different types of cellular events through interactions between carbohydrates and proteins. There are three main families of CBPs.

1. the C-type lectin family (including the Selectins)
2. the Siglec family
3. the galectin family

C-type Lectins (including Selectins)

C-type Lectins and selectins are present in humans and murines (household rats and mice). Roles of these specific CBPs include

• promoting primary immune response
• mediating leukocyte trafficking to sites of inflammation
• mediating lymphocyte recirculation
• mediating platelet binding to neutrophils

Clinical Use of Lectins

Pure forms of lectins are used for blood typing. Specifically, lectins are used to identify some glycolipids and glycoproteins on an individual's red blood cells. In the brain, PHA-L, a lectin from a kidney bean, helps to trace the path of efferent axons through the anterograde labeling method.

PHA-L

Siglecs

Siglecs occur mostly in humans, but some are also found in murines. Some of the primary roles of these CBPs are:

• regulator in B cell activation
• maintenance of myelin
• inhibitor of axonal growth

Galectins

Galectins are also found in humans, mice, and rats as well. These CBPs are abundant in most organs such as muscles, hearts, lung, liver, lymph nodes, thymus, and colon, stomach epithelial cells, gastrointestimal, erythrocytes, skin, brain, Hodgkin's lymphoma, kidney, and lens. Roles include:

• acting as a marker for cell recognition
• binding specificity

References

http://web.mit.edu/glycomics/consortium/organization/program/program1.pdf