Protein microarrays allow high-throughput analysis of protein interactions and functions. They consist of large numbers of capture proteins immobilized on a surface to which labeled probe molecules are added to detect reactions by fluorescence. There are analytical arrays to study protein binding properties and functional arrays containing full-length proteins to assay enzymatic activity and detect antibodies. Protein microarrays have applications in diagnostics, proteomics, analyzing protein interactions and functions, antibody characterization, and treatment development.

1. PROTEIN MICROARRAY
K.KRUPA SAGAR
M.Pharm 1st year

2. INTRODUCTION
• Protein micro array(or Protein chip) is a high-
throughput method used to track the interactions
& activities of proteins, to determinate their
functions.
• Protein micro array are rapid, automated,
economical and highly sensitive consuming only
small quantities of samples and reagents.

3. HISTORY
• Micro array technology was first developed from
an earlier concept called “Ambient analyte
immunoassay” by Roger Ekins in 1989.
• Later transformed into DNA microarray.
• Due to some limitations in DNA microarray ,
this protein microarray was developed to
overcome those limitations.

4. PRINCIPLE

5. • Protein chip consists of a support surface such
as glass slide, nitrocellulose, bead or
microtitreplate to which array of capture
proteins is bound.
• Probe molecules typically labeled with a
fluorescent dye are added to the array.
• Any reaction between the probe and the
immobilized protein emits a fluorescent
signal and that is read by laser scanner.

6. TYPES OF ARRAY’S:
• Antigen capture
format
• Sandwich format
1.ANALYTICAL
PROTEIN
MICROARRAY
• Biochemical properties
of proteins such as
binding activities =>
• P-P,P-DNA,P-Lipid,
• P-Peptide
2.FUNCTIONAL
PROTEIN
MICROARRAY

7. ANALYTICAL PROTEIN MICROARRAY

8. FUNCTIONAL PROTEIN
MICROARRAY

9. • Functional protein microarray (target protein
array) are constructed by immobilizing large
num of proteins to assay enzymatic activity and
to detect antibodies & their functions.
• They differ from analytical protein microarray
by containing full length functional proteins or
protein domains.

10. • These are used to study the biochemical
activities of entire proteome in a single
experiment.
• The proteins must retain their native or original
structure so that meaningful functional
interactions takes place on the array surface.

11. 3.REVERSE PHASE PROTEIN
MICROARRAY

12. DETECTION SYSTEMS
LABEL - DEPENDENT LABLE- FREE
Several types of labeling
reagents like fluorescent
dyes(Cy3& Cy5),
enzymes(Horseradish peroxides),
radio isotopes (32P, 33P & 14C),
liposome's are used.
Rolling circle amplication (RCA)
Tyramide signal amplication(TSA)
used to detect low abundance
proteins.
Label dependent may effect the
protein activity.
Surface Plasmon Resonance
Spectroscopy (SPRS)
Optical Elipsometry (OE)
Reflectometric Interference
Spectroscopy(RIFS)
Oblique-incidence reflectivity
difference(OIRD)

13. APPLICATIONS
• Mainly used in 5 major areas
• Diagnostics
• Proteomics
• Protein functional analysis
• Antibody characterization &
• Treatment development

14. •Diagnostics:
Detection in antigen antibodies in blood sample
To discover new disease biomarkers; monitoring the
diseased state and responses to therapy.
Ex: Digital bioassay
Proteomics:
Protein expression profiling i.e., which proteins are
expressed in a particular cell.

15. Protein functional analysis:
To identify :-
Protein-protein interactions
Protein- phospholipids interactions
Enzymatic substrates &
Receptor ligands

16. Antibody characterization:
characterization of cross reactivity, specificity and
mapping epitopes.
Treatment development:
 Development of antigen- specificity therapies for
autoimmunity , cancer and allergies.
 Identification of small molecules that could potentially
used to be as new drugs