1. Online Counseling Resource YCMOU ELearning Drive… School of Architecture, Science and Technology Yashwantrao Chavan Maharashtra Open University, Nashik – 422222, India

2. SEP-SBI072-U01-CP-02 Introduction Programmes and Courses SEP –SBT072- U01 -CP_02

3. School of Science and Technology, Online Counseling Resource… Credits  Academic Inputs by Sonali Alkari Faculty YCMOU Nagpur Centre, Faculty LAD college P.G. D of Biotechnology Research officer Ankur Seeds Pvt Ltd sonalisa_alkari@yahoo.co.in Sonalisaal@rediffmail.com

4. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.4 How to Use This Resource  Counselor at each study center should use this presentation to deliver lecture of 40-60 minutes during Face-To-Face counseling.  Discussion about students difficulties or tutorial with assignments should follow the lecture for about 40-60 minutes.  Handouts (with 6 slides on each A4 size page) of this presentation should be provided to each student.  Each student should discuss on the discussion forum all the terms which could not be understood. This will improve his writing skills and enhance knowledge level about topics, which shall be immensely useful for end exam.  Appear several times, for all the Self-Tests, available for this course.  Student can use handouts for last minutes preparation just before end exam.

5. School of Science and Technology, Online Counseling Resource… © 2007, YCMOU. All Rights Reserved.5 Learning Objectives  After studying this module, you should be able to: Discuss importance of data visulization Factors affecting structure of molecules. Various visulization Tools: Rasmol, VMD, Swiss-PDB viwer, Cn3D

6. School of Science and Technology, Online Counseling Resource… Glycoproteins  Glycoproteins are proteins that contain oligosaccharide chains (glycans) covalently attached to their polypeptide side-chains.  The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation.  In proteins that have segments extending extracellularly, the extracellular segments are often glycosylated.  Glycoproteins are often important integral membrane proteins, where they play a role in cell-cell interactions. © 2007, YCMOU. All Rights Reserved.6

7. School of Science and Technology, Online Counseling Resource… Glycoproteins  The attachment is a covalent linkage to: the hydroxyl (-OH) group of the R group of serine or threonine - called "O-linked" in both cases or to the amino group (-NH 2 ) in the R group of asparagine - called "N-linked".  The sugars on glycoproteins have been placed there by glycosylation — a precise enzymatic activity that makes a product which would otherwise not function correctly.  However, sugars can also spontaneously form covalent links to proteins (and lipids) — a process called glycation. No enzymes are involved so the process is quite random. The products are apt to have reduced, or even no, function. © 2007, YCMOU. All Rights Reserved.7

8. School of Science and Technology, Online Counseling Resource… Examples  The glycophorin A, a glycoprotein that spans the plasma membrane ("Lipid bilayer") of human red blood cells.  Each RBC has some 500,000 copies of the molecule embedded in its plasma membrane.  Glycophorin A is the most important attachment site by which the parasite Plasmodium falciparum invades human red blood cells.  Two polymorphic versions of glycophorin A, which differ only at residues 1 and 5, occur in humans. © 2007, YCMOU. All Rights Reserved.8

9. School of Science and Technology, Online Counseling Resource… Examples © 2007, YCMOU. All Rights Reserved.9

10. School of Science and Technology, Online Counseling Resource… Examples  One example of glycoproteins found in the body is mucins, which are secreted in the mucus of the respiratory and digestive tracts. The sugars attached to mucins give them considerable water-holding capacity and also make them resistant to proteolysis by digestive enzymes.  Glycoproteins are important for white blood cell recognition, especially in mammals.  Examples of glycoproteins in the immune system are: molecules such as antibodies (immunoglobulins), which interact directly with antigens molecules of the major histocompatibility complex (or MHC), which are expressed on the surface of cells and interact with T cells as part of the adaptive immune response. © 2007, YCMOU. All Rights Reserved.10

11. School of Science and Technology, Online Counseling Resource… Hormones that are glycoprotein  Follicle-stimulating hormone  Luteinizing hormone  Thyroid-stimulating hormone  human chorionic gonadotropin  Alpha-fetoprotein  Erythropoietin (EPO) © 2007, YCMOU. All Rights Reserved.11

12. School of Science and Technology, Online Counseling Resource… Proteoglycan  Proteoglycans represent a special class of glycoproteins that are heavily glycosylated.  They consist of a core protein with one or more covalently attached glycosaminoglycan (GAG) chain(s).  These glycosaminoglycan chains are long, linear carbohydrate polymers that are negatively charged under physiological conditions, due to the occurrence of sulfate and uronic acid groups.  Individual functions of proteoglycans can be attributed to either the protein core or the attached GAG chain. © 2007, YCMOU. All Rights Reserved.12

13. School of Science and Technology, Online Counseling Resource… Proteoglycan  The protein component of proteoglycans is synthesized by ribosomes and translocated into the lumen of the rough endoplasmic reticulum.  Glycosylation of the proteoglycan occurs in the Golgi apparatus in multiple enzymatic steps.  First a special link tetrasaccharide is attached to a serine side chain on the core protein to serve as a primer for polysaccharide growth.  Then sugars are added one at the time by glycosyl transferase.  The completed proteoglycan is then exported in secretory vesicles to the extracellular matrix of the cell. © 2007, YCMOU. All Rights Reserved.13

14. School of Science and Technology, Online Counseling Resource… Proteoglycan  Proteoglycans are a major component of the animal extracellular matrix, the "filler" substance existing between cells in an organism.  Here they form large complexes, both to other proteoglycans, to hyaluronan and to fibrous matrix proteins (such as collagen).  They are also involved in binding cations (such as sodium, potassium and calcium) and water, and also regulating the movement of molecules through the matrix.  Evidence also shows they can affect the activity and stability of proteins and signalling molecules within the matrix. © 2007, YCMOU. All Rights Reserved.14

15. School of Science and Technology, Online Counseling Resource… Proteoglycan  An inability to break down proteoglycans is characteristic of a group of genetic disorders, called mucopolysaccharidoses.  The inactivity of specific lysozomal enzymes that normally degrade glycosaminoglycans leads to the accumulation of proteoglycans within cells.  This leads to a variety of disease symptoms, depending upon the type of proteoglycan that is not degraded. © 2007, YCMOU. All Rights Reserved.15

16. School of Science and Technology, Online Counseling Resource… What You Learn…  You have learnt : Glycoproteins are proteins that contain oligosaccharide chains (glycans) covalently attached to their polypeptide side-chains. Glycoproteins are often important integral membrane proteins, where they play a role in cell-cell interactions. Proteoglycans represent a special class of glycoproteins that are heavily glycosylated. The inactivity of specific lysozomal enzymes that normally degrade glycosaminoglycans leads to the accumulation of proteoglycans within cells.

17. School of Science and Technology, Online Counseling Resource… Critical Thinking Questions 1.Write a short note on glycoprotein and their role. 2.Describe proteoglycan and effect of lysozozymes ? © 2007, YCMOU. All Rights Reserved.17

18. School of Science and Technology, Online Counseling Resource… Hints For Critical Thinking Question 1.Proteins that contain oligosaccharide chains (glycans) covalently, glycosylation, role of glycoprotein in immune system and harmones. 2.Proteoglycans represent a special class of glycoproteins that are heavily glycosylated. The inactivity of specific lysozomal enzymes that normally degrade glycosaminoglycans leads to a variety of disease symptoms, depending upon the type of proteoglycan that is not degraded. © 2007, YCMOU. All Rights Reserved.18

19. School of Science and Technology, Online Counseling Resource… Study Tips:1  Book1 Title: Molecular Cell Biology Author: Harvey Lodish, David Baltimore Publisher:Publishers: W. H. Freeman and Company  Book2 Title: Principles of Biochemistry Author: AlbertL Lehninger Publisher:CBS Publishers & Distributors

20. School of Science and Technology, Online Counseling Resource… Study Tips:2  Book3 Title: Biochemistry Author: Lubert stryer Publishers: Freeman International  Book4 Title: Biochemistry Author: Keshav Trehan Publishers: Wiley Eastern

21. School of Science and Technology, Online Counseling Resource… Study Tips www.en.wikipedia.org Microsoft Encarta Encyclopedia http://en.wikipedia.org/wiki/ Wikipedia the free encyclopedia

22. School of Science and Technology, Online Counseling Resource… End of the Presentation Thank You