Protein Analysis and Sequencing Techniques

Flashcards covering key concepts and techniques in protein analysis and sequencing, including ELISA, blotting methods, and protein structure determination.

SDS-PAGE

A technique that looks for the presence of a protein of a specific size.

Antibodies

Biological molecules providing high specificity in detection techniques by binding exclusively to a target molecule.

ELISA (Enzyme-linked Immunosorbent Assay)

A technique based on specific antibody-antigen interaction used to find target proteins or antibodies.

Antigen

The specific target protein that an antibody binds to, often sought in techniques like Sandwich ELISA.

Sandwich ELISA

An ELISA method used to detect a specific target protein (antigen) by first binding antigens to antibodies attached in a well, then using a second antibody for detection.

Indirect ELISA

An ELISA method used to detect the presence of antibodies against a specific antigen, indicating prior exposure to an antigen.

Standard Curve (in ELISA)

A quantitative tool in ELISA where known concentrations of a substance are measured to create a graph, which is then used to determine the concentration of unknown samples.

Southern Blotting

A technique developed by Southern to detect a particular DNA sequence using a DNA probe.

DNA Probe

A complementary DNA sequence used to bind specifically to a target DNA sequence in blotting techniques.

Western Blotting

A technique that uses antibodies to specifically detect a target protein after proteins have been separated by SDS-PAGE and transferred to a membrane.

Blotting/Transfer (in Western Blotting)

The process of making a copy of separated proteins from an SDS gel onto a polymer matrix sheet, allowing for subsequent specific detection.

Autoradiography

A detection method that uses radioactive decay from a labeled sample to expose and develop photographic film, revealing the location of the labeled molecule.

Autoradiogram

The photographic film produced by autoradiography, showing the distribution of a radioactive substance.

Protein Primary Sequence

The specific linear order of amino acids in a polypeptide chain, crucial for determining a protein's function and three-dimensional structure.

X-ray Crystallography

A technique used to determine the three-dimensional structure of proteins by analyzing the diffraction pattern created when X-rays are diffracted by a protein crystal.

Amino Acid Composition

The determination of the types and proportional quantities of amino acids present in a peptide or protein after complete hydrolysis.

Acid-catalyzed Hydrolysis (of Peptides)

The chemical breakdown of peptide bonds using concentrated HCl and heat, yielding individual free amino acids.

Asparagine (hydrolysis product)

When subjected to strong acid-catalyzed hydrolysis, asparagine is converted to aspartic acid.

Glutamine (hydrolysis product)

When subjected to strong acid-catalyzed hydrolysis, glutamine is converted to glutamic acid.

Edman Degradation

A sequential method for determining the primary sequence of a peptide by cleaving and identifying one amino acid at a time from the N-terminus.

Carboxypeptidase

An exopeptidase enzyme that catalyzes the cleavage of amino acids sequentially from the C-terminus (carboxy terminus) of a peptide.

Cyanogen Bromide

A chemical reagent that specifically cleaves peptide bonds on the C-terminal side of methionine residues.