Chapter 3: Protein Structure and Function Flashcards
(254 cards)
1
Q
Protein is derived from the greek wor ____ meaning ____
A
proteios means “first”
2
Q
Why does the term protein derived from the Greek word proteios?
A
To indicate the central roles that proteins play in the living organisms
3
Q
the indespensable agents of biological function
A
Proteins
4
Q
building blocks of proteins
A
Amino acids
5
Q
The stunning diversity of the thousands of proteins found in nature arises from the intrinsic properties of _ _ _ _ _ _
A
only 20 commonly occurring amino acids
6
Q
These features include:
A
- the capacity to polymerize
- novel acid-base properties
- varied structure and chemical functionality in the amino acid side chains
- Chirality
7
Q
- or handedness
- means that an object or molecule cannot be superimosed on its mirror image by any translation or rotations
A
Chirality
8
Q
Classification of proteins
A
Structural
Contractile/Movement
Transport
Storage/Nutrient
Hormone/Regulatory
Enzyme
Protection/Defense
9
Q
- are biological catalysts
- majority of this that have been studied are proteins
A
Enzymes
10
Q
Function of Enzyme
A
Catalyze biochemical reactions in the cells
11
Q
Examples of Enzyme
A
- Sucrose
- Trypsin
12
Q
It catalyzes the hydrolysis of sucrose
A
Surcose
13
Q
It catalyzes the hydrolysis of proteins
A
Trypsin
14
Q
Example of the function of Enzymes
A
Digestive enzymes pepsin, trypsin, and chymotrypsin break down proteins in our diet so that subunits can be absorbed for use by our cells
15
Q
Without _ , the body
cannot _ _
A
- enzymes
- absorb nutrients
16
Q
- it includes antibodies
- specific protein molecules produced by specialized cells of the immune system in response to foreign antigens
A
Protection or Defense proteins
17
Q
Antibodies also called as
A
Immunoglobulins
18
Q
These foreign invaders include _ and _ that infect the body
A
bacteria and viruses
19
Q
Each _ has regions that precisely fit and bind to a single _
A
- each antibody
- antigen
20
Q
Antibody helps to end the ___ by _____ to the ______ and helping to _____ it or ______ it from the body.
A
- infection
- binding to the antigen
- destroy
- remove
21
Q
Function of Protection/Defense Protein
A
Recognize and destroy foreign substances
22
Q
Example of Protection/Defense Protein
A
Immunoglobulins
23
Q
It stimulate immune responses
A
Immunoglobulins
24
Q
carry materials from one place to
another in the body
A
Transport proteins
25
The protein that transports iron from the liver to the bone marrow
Transferrin
26
Transferrin is used to
it is used to synthesize the
heme group for hemoglobin
27
Transferrin is ______ and _______ into ____ mostly by the ___
- synthesized and secreted
- serum
- liver
28
Synthesis of transferrin is regulated by _____
iron
29
Iron alone is _______ ______
extremely reactive
30
If iron is not bound by specific _____ ____ and/or _____ _____ within the body, it can _____ ____ with ____, _____, and _____ structures
- serum carriers
- storage proteins
- viciously interact
- vascular, cellular, and subcellular
31
Therefore, after absorption, it is bound to the _______ ____ _____ (TF) for ____ _____
- plasma protein transferrin
- safe transport
32
The proteins that are responsible for transport and storage of oxygen in higher organisms, respectively
Hemoglobin and myoglobin
33
Function of Transport proteins
carry essential substances throughout the body
34
Example of Transport proteins
- Hemoglobin
- Lipoproteins
35
transports oxygen
Hemoglobin
36
transport lipids
Lipoproteins
37
Structural Differences of Myoglobin and Hemoglobin:
Myoglobin
- 1 subunit
- heme group
38
Structural Differences of Myoglobin and Hemoglobin
Hemoglobin
- 4 subunits
- 4 hemegroups
39
- it controls many aspects of cell function, inlcuding metabolism and reproduction
- can only function within a limited set of conditions
Regulatory/Hormone proteins
40
Function of Regulatory/Hormone protein
Regulate body metabolism and the nervous system
41
In regulatory proteins, what must be carefully regulated for life to exist?
- body temperature
- the pH of the blood
- blood glucose levels
42
Example of Regulatory/Hormone proteins
- Insulin
- Growth hormone
43
It regulates blood glucose level
Insulin
44
A hormone that regulate body function (proteins)
Insulin and Glucagon
45
The hormone that preps your body to cope with stress
Adrenaline: Fight or Flight
46
How your body creates Adrenaline cells?
- eating high-protein foods,your liver extracts amino acids and sends them to the adrenal glands where they get reshaped into adrenaline and stores
47
How your body uses Adrenaline cells?
EMERGENCY
- your adrena glands release adrenaline into the blood in a "mass discharge", your body shifts into "fight or flight" mode
48
Adrenaline: Fight or Flight
More blood travels to your brain:
Your mind is sharper
49
Adrenaline: Fight or Flight
Pupils dilate:
Your vision is clearer
50
Adrenaline: Fight or Flight
The airways in the lungs dilate:
Taking in more oxygen
51
Adrenaline: Fight or Flight
The hearts contracts more forcefully:
Pumps out more blood
52
Adrenaline: Fight or Flight
Sweat:
You sweat more
53
Adrenaline: Fight or Flight
The blood clots more readily:
Helps minimize blood loss
54
Adrenaline: Fight or Flight
The available source of fuel:
Blood levels of cholesterol, glucose and fatty acids, increases
55
Adrenaline: Fight or Flight
Skeletal muscles:
More blood gets more oxygen and glucose which strengthen the skeletal muscles
56
Adrenaline: Fight or Flight
Hunger is no longer a priority:
Blood vessels feeding the gastrointestinal tract narrow and digestive movements slow
57
How many minutes does these adrenalized effects last?
1 or 2 minutes
58
What happens to the adrenaline chamiclas after the threat passes?
The adrenaline chemicals oxidize and are converted into waste-product chemicals and are shipped out in urine
59
It provides mechanical support to large animals and provide them with their outer coverings
Structural proteins
60
Function of Structural proteins
Provide structural components
61
Example of Structural proteins
- Collagen
- Keratin
62
It is in tendons and cartilage
Collagen
63
It is in hair, skin, wool, and nails
Keratin
64
Which part of our body that are largely composed of the protein keratin?
Hair and fingernails
65
What is EB?
Epidermolysis bullosa
66
Babies that are born with EB are known as?
"butterfly babies"
67
People with EB have __ ___ resulting to ___ ____ ___ in the skin
- genetic mutation
- abnormal structural proteins
68
What is the effect of recessive Dystrophic EB?
- difficulty to ingest food for a child
- causes blistering that occurs in mouth, esophagus, and gastrointestinal tract
69
It is necessary for all forms of movement
Movement/Contractile proteins
70
Function of movement/contractile protein
Make muscles move, including the heart
71
Example of Movement/Contractile protein
- Myosin
- Actin
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It contracts muscle fibers
Myosin and actin
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It serve as sources of amino acids for embryos or infants
Nutrient proteins
74
Examples of Storage/Nutrient protein
- Casein
- Ferritin
- Egg albumen
75
It stores protein in milk
Casein
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It stores iron in the spleen and liver
Ferritin
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these compounds contain both an amine and an acid
Amino acids
78
20 amino acids that are common in nature are all?
All 20 are α-amino acids
79
α (alpha) means
amine is adjacent to the carboxylate group
80
Out of all 20 amino acids, how many are stereoisomers?
19
81
What amino acid is not a stereoisomer out of all 20 common amino acid?
Glycine (does not have a chiral carbon)
82
The α-carbon of amino acids is ____
Chiral
83
What is a chiral molecule?
It is non-superposable to its mirror image due to the presence of an asymmetric carbon atom
84
Where does all the differences between amino acids depens upon?
side-chain R groups
85
Forming classes of Amino acids is based on, what?
Polarity of their side chains
86
Classes of Amino Acids
- Nonpolar
- Polar, neutral
- Polar acidic
- Polar basic
87
It is a class of amino acid that has hydrophobic R groups
Nonpolar
88
It is a class of amino acid that have a high affinity for water, but are not ionic at pH
Polar, neutral
89
- it is a class of amino acid that have ionized carboxyl groups in their side chains
- negatively charged
Polar acidic
90
- are basic as the side chain reacts with water to release a hydroxide anion
- positively charged
Polar basic
91
What are the amino acids that are essential for normal tissue growth and development?
All amino acids
92
What is the term that is reserved for those amino acids that must be supplied in the diet for proper growth and development?
"essential amino acids"
93
“PVT. TIM HALL”
Phe, Val, Thr, Trp, Ile, Met, His, Arg, Leu, Lys
94
___ and ___ are semi-essential; they not synthesized in sufficient quantities during infancy stage
His and Arg
95
α-carbon is attached to a:
- Carboxyl group (̶ COOH)
- Amino group ( ̶ NH2)
96
At physiologic pH the amino acid has:
- Carboxyl group in –COO-
- Amino group in –NH3+
- Neutral molecule with equal number of + and – charges is called a zwitterion
97
What is a zwitterion?
Neutral molecule with equal number of + and – charges
98
From the German word "zwitter" which means
hybrid or hermaphrodite
99
Amino acids are __ ____ __ with __ ___ __ and __ ___ ___
- white crystalline solids
- high melting points
- high water solubilities
100
What are the two charged groups?
- basic amino group
- carboxylic acid
101
The two charged groups at the two ends lead to
internal proton transfer, forming zwitterions
102
By changing the __ you can affect the __ ___ on the zwitterions
- pH
- net charge
103
It is the pH point at which there is no net charge on the zwitterions
Isoelectric point (pI)
104
What is the isoelectric point of an amino acid?
the pH at which it bears no net charge
105
What is a form of acid that is more accurate depiction of its structure?
Zwitterionic
106
A ____ contains two point charges but is ___ overall
- zwitterion
- neutral
107
At pH values below isoelectric point
bear net positive charge
108
At pH above isoelectric point
bear net negative charge
109
It is a test by applying a sample of the amino acid to specially treated paper or gel and applying an electric field at different pH values
Electrophoresis
110
A molecule with a net charge of zero will __ migrate in an electric field
not
111
positive charge (+) will migrate toward
cathode (-)
112
negative charge (-) will migrate toward
anode (+)
113
For a typical amino acid with a neutral sidechain R:
- the positively charged form (+1) dominates at low pH
- the zwitterionic (neutral) form dominates at intermedaite pH
- the negatively charged form (-1) dominates at high pH
114
For an amino acid with an acidic sidechain:
- the positively chargde form (+1) dominates very low pH
- the zwitterionic (neutral) form dominates at low pH
- the negatively charged form (-1) dominates at intermediate pH
- at strong basic pH a doubly negatively charged form (-2) may form
115
For an amino acid with a basic sidechain (e.g. lysine)
- the doubly positive charged form (+2) dominates at very low pH
- the positively charged form (+1) dominates at intermediate pH
- the zwitterionic form (neutral) forms at basic pH
- at strongly basic pH, the negatively charged form (-1) dominates
116
What is the pI values of the polar acidic amino acids?
pH 3
117
What are the polar acidic amino acids?
- Aspartic acid
- Glutamic acid
118
The carboxylic acid in R groups of their zwitterions at pH 3 is __ ___
Not ionized
119
The carboxylic acid in R groups at physiological pH __ _ to form a ___ ___ `
- loses H+
- negatively charged
120
What is the pI values of basic amino acids?`
typically higher than physiological pH value, ranging from pH 7.6 to 10.8
121
The amines in the R groups of the basic amino acids at physiological pH values __ _ to form an ___ ___ __
- gain H+
- overall positive charge
122
What are the basic amino acids?
- lysine
- arginine
- histidine
123
Amino acid:
Neutral
Isoelectric pH:
4.8 - 6.3
124
Example of Neutal Amino Acid
Ala (6.1)
125
Amino acid:
Acidic
Isoelectric pH:
2.8 - 3.2
126
Example of Acidic Amino Acid
Asp (2.8)
127
Amino acid:
Basic
Isoelectric pH:
7.8 - 10.8
128
Example of Basic Amino Acid
Lys (9.7)
129
It is an analytical method for identifying amino acids by observing their migration as a function of pH under an applied electric field gradient
Electrophoresis
130
If an amino acid carries a positive charge at pH
migrate to the negative electrode (cathode)
131
If an amino acid carries a negative charge at pH>pI, it will ___
migrate to the positive charge electrode (anode)
132
What are the techniques in separating amino acids?
1. Ion-exchange chromatography
2. Size-exclusion chromatography
3. Affinity chromatography
133
Ion-excahnge chromatography
Separates the compounds base on charge
134
Size-exclusion chromatography
Separates compounds base on size
135
Affinity chromatography
Separates the compounds base on the interaction between the protein of interest and ligand
136
A result of covalent bonding between the amino acids
The Peptide Bonds
137
In peptide bonds, proteins are?
linear polymers of L-α-amino acids
138
The peptide bond:
Carboxyl group of one amino acid is linked to ___
the amino group of another amino acid
139
It is an amide bond or peptide linkage
Linkage
140
What is the reaction involve in peptide bond?
Dehydration reaction
141
What is produce if the two amino acids are condensed or dehydrated?
Dipeptide
142
N-terminal amino acid
Amino acid with a free a-NH3+ group
143
C-terminal amino acid
Amino acid with a free –COO ̶ group
144
Amino acid structures are written with the ___
N-terminal on the left
145
amino acids are polymerized into ___ and ___
peptides and proteins
146
It is used for molecules composed over 50 amino acids
Protein
147
It is used for molecules of less than 50 amino acids
Peptide
148
Naming Peptides
- The far right AA residue retains the name of the amino acid
- All AAs (except TRYPTOPHAN) → - ine or –ic acid is replaced by –yl
- Tryptophan becomes tryptophanyl
149
Small Peptides
1. Aspartame (Asp-Phe)
2. Glutathione (Glu-Cys-Gly)
3. Enkephalins (Tyr-Gly-Gly-Phe-Leu & Tyr-Gly-Gly-Phe-Met)
4. Oxytocin (Ile-Leu)
5. Vasopressin (Phe-Arg)
150
- it is the artificial sweetener used in almost every diet food on the market today
- its caloric content is the same as sucrose but is ~180 times as sweet
Aspartame (Asp-Phe)
151
Forms have a bitter taste
- L-D
- D-L
- D-D
152
- it functions as an antioxidant, protecting cellular contents from oxidizing agents such as peroxides and superoxides
Glutathione (Glu-Cys-Gly)
153
What are the oxidizing agents that are highly reactive forms of oxygen often generated within a cell?
Peroxides and Superoxides
154
Glu is bonded to Cys through the ___ ___ ___ rather than through the ___ ____ ___
- side-chain carboxyl group
- α-carbon carboxyl group
155
- natural painkillers produced in the body
- it is bind to receptors in the brain to give relief from pain
Enkephalins and Endorphins
156
- it is the first hormone to be synthesized in the laboratory
- a nonpeptide used to initiate labor
Oxytocin
157
Oxytocin stimulates ____ _____ in labor
uterine contractions
158
- an antidiuretic hormone
- regulates blood pressure by adjusting the amount of water reabsorbed by the kidneys
Vasopressin
159
- partly responsible for triggering pain, welt formation (as in scratches), movement of smooth muscle, and lowering of blood pressure
Bradykinin (Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg)
160
completely inactive, hence, the name bogus or false
Boguskinin (Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe- )
161
Val-His-Leu-Thr-Pro-Glu-Glu-Lys-Ser-Ala-
Normal Hb
162
Val-His-Leu-Thr-Pro-Val-Glu-Lys-Ser-Ala-
Sickle-cell Hb
163
Val-His-Leu-Thr-Pro-Glu-Lys-Lys-Ser-Ala-
Georgetown anemia
164
The sickled cells are unable to pass through the ___ _____ of the circulatory system, and circulation is ____
- small capilliaries
- hindered
165
Effect of sickled cells in human body
- damage to many organs (bone and kidney)
- can lead to death at an early age
166
It is results from formation of covalent peptide bonds between amino acids
Primary Structure of Proteins
167
What is the Primary Structure of Proteins?
The amino acid sequence of the polypeptide chain
168
The peptide bond has a __ ___ __ character
partial double bond
169
There is __ ___ around __ __ of the three single bonds of a peptide backbone
- free rotation
- only two
170
R groups on adjacent amino acids are on ____ ___ of the chain because of the rigid peptide bond.
Opposite sides
171
How does the Second Structure of Proteins is formed?
When the primary sequence of the polypeptide folds into regularly repeating structures
172
Secondary structure results from ___ ___ between the _____ ___ and ______ ___ of the peptide bonds
- hydrogen bonding
- amide hydrogens (N—H)
- carbonyl oxygens (C=O)
173
Most common type of secondary structure
- Coiled
- Helical
174
Secondary Sructure of Proteins includes:
α-helix and β-sheet
175
Important features of Secondary Structure of Proteins: α-Helix
- Each amide H and carbonyl O is involved in H bonds locking the helix in place
- Carbonyl O links to amide H 4 amino acids away
- H bonds are parallel to the long axis of the helix
- Helix is right-handed
- Repeat distance or pitch is 5.4 angstroms
- 3.6 amino acids per turn
176
In α-Helix, the borken line represents the? (tanawa lng nnyo sa pdf na gi send ni maam ang picture hehe sankss)
Hydrogen bonds
177
What is the direction Hydrogen bonds in α-Helix?
Parallel to the direction of the helix
178
are arranged in a secondary structure of fibers or sheets with only 1 type of secondary structure
Fibrous proteins
179
- it is the second most common secondary structure
- appears similar to folds of fabric
β-pleated sheet
180
In β-pleated sheet, what organic compounds that are involved in the H bonds with the chain nearly completely extended?
- carbonyl O
- amide H
181
β-pleated sheet:
Two possible orientation
1. Parallel
2. Antiparallel
182
Two possible orientation:
Parallel
The N-termini are head-to-head
183
Two possible orientation:
Antiparallel
The N-terminus of one chain is aligned with the C-terminus of the other
184
- three-dimensional structure
- overall folding of the entire polypeptide chain
- defines the biological function of proteins
The Tertiary Structure of Proteins
185
- forms spontaneously
- maintained by interactions among the side chains or R groups
Globular tertiary structure
186
Types of Interactions Maintaining Tertiary Structure
1. Disulfide bridges
2. Salt bridges
3. Hydrogen bonds
4. Hydrophobic interactions
187
Disulfide bridges
interaction between two cysteine residue
188
Linkage that occurs within the same chain
Intrachain
189
Linkage the occurs between 2 or more chains
Interchain
190
Salt bridges
- ionic interaction/electrostatic attraction
- interaction between ionic side chains –COO– and –NH3+
191
Hydrogen bonds
Interaction between polar residue side chains
192
Hydrophobic interactions
two nonpolar groups are attracted by a mutual repulsion of water
193
- it is the arrangement of subunits or peptides that form a larger protein
- is maintained by the same forces which are active in maintaining tertiary structure
The Quaternary Structure of Proteins
194
What is the functional form of many proteins?
Aggregate of several globular peptides
195
A polypeptide chain having primary, secondary, and tertiary structural features that is a part of a larger protein
Subunit
196
Protein Functions Follow Shape
Fibrous proteins:
- Mechanical strength
- Structural components
- Movement
197
Protein Functions Follow Shape
Globular proteins:
- Transport
- Regulatory
- Enzymes
198
Shape of Globular proteins
Roughly circular
199
Shape of Fibrious proteins
Long strands
200
Amino acid sequence of Globular proteins
Irregular and wide range of R groups
201
Amino acid sequence of Fibrious proteins
Repetitive with a limited range of R groups
202
Function of Globular proteins
Physiological/functional
203
Function of Fibrious proteins
Structural
204
Examples of Globular proteins
- Hemoglobin
- Enzymes
- Insulin
- Immunoglobulin
205
Examples of Fibrous proteins
- Collagen
- Keratin
- Myosin
- Actin
- Fibrin
206
Solubility of Globular proteins
(generally) soluble in water
207
Solubility of Fibrous proteins
(generally) insoluble in water
208
Hemoglobin in Normal (wild-type)
Normal (Globular)
209
Red Blood Cell in Normal (wild-type) Hemoglobin
Round (biconcave)
210
Blood Vessels in Normal (wild-type) Haemoglobin
Free flowing
211
Hemoglobin in 'Sickle Cell'
Clumped (fibrous)
212
Red Blood Cell in 'Sickle Cell' Hemoglobin
Sickle-shaped
213
Blood Vessels in 'Sickle Cell' Hemoglobin
Forms clots/blockages
214
It is a protein to which another chemical group (e.g., carbohydrate) is attached by either covalent bonding or other interactions
Conjugated Proteins
215
It is the oxygen storage protein of skeletal muscle
Myoglobin
216
It is the oxygen-transport protein of higher animals
Hemoglobin
217
Why does the oxygen is transferred from hemoglobin to myoglobin?
Since the myoglobin has a stronger attraction for oxygen than hemoglobin does
218
It is an essential component of the proteins hemoglobin and myoglobin
Heme group
219
In the heme group, it is the oxygen binding site
Fe2+, ferous ion
220
Each hemoglobin contains a ___ ___ which can hold __ ____ of oxygen (O2)
- heme group
- 1 molecule
221
Hemoglobon
T-form:
- taut or tense
- Deoxy: low O2 affinity
222
Hemoglobon
R-form:
- relaxed
- Oxy: high O2 affinity
223
The disruption of bonds in the secondary, tertiary, and quaternary protein structures
Protein Denaturation
224
It is the loss of organized structure of a globular protein
Denaturation
225
It is the breaking of bonds using water
Hydrolysis
226
- splits the peptide bonds to give smaller peptides and amino acids occurs in the digestion of proteins
- occurs in cells when amino acids are needed to synthesize new proteins and repair tissues
Protein Hydrolysis
227
In the lab, the hydrolysis of a peptide requires __ or ___, ___, and ___
acid or base, water, and heat
228
In the body, _____ catalyze the hydrolysis of proteins
Enzymes
229
Some practical aspects of protein denaturation
1. Heat and UV
2. Salts of heavy metal ions esp. Hg2+, Pb2+, Ag+
3. Organic compounds such as soap, detergents, phenol, and aliphatic alcohol
230
Protein Sequencing
Steps in determining the amino acid sequence:
1. hydrolysis - by acid, alkali, or enzyme
2. identification of the products of hydrolysis
3. fitting the pieces together as you would a jigsaw puzzle
231
Protein Sequencing
HYDROLYSIS
1. Acid Hydrolysis
2. Alkali Hydrolysis
3. Cyanogen bromide
4. Enzymatic Hydrolysis by proteases/ peptidases
232
- involves heating in the presence of 6N HCl
- the protein is completely hydrolyzed, but Trp, is destroyed completely and Ser, Thr, and Tyr are partially destroyed
Acid Hydrolysis
233
- heating in the presence of 4N NaOH
- does not damage Trp, but destroys Arg, Cys, Thr, & Ser; and some amino acids are partly deaminated
- more disadvantageous
- it is used in quantitative determination of this amino acid
Alkali Hydrolysis
234
- cuts peptide bonds on the carboxylterminal side of methionine residues
- used to reduce the size of polypeptide segments for identification and sequencing
Cyanogen bromide
235
Two types of Enzymatic Hydrolysis
1. Exopeptidases
2. Endopeptidases
236
Enzymes that cleave external peptide bonds
Exopeptidases
237
Exopeptidases is used in __
the determination of the amino
acid sequence of peptides
238
Enzymes under Exopeptidases
1. Aminopeptidases
2. Carboxypeptidases
239
It sequentially cleaves peptide bonds, beginning at the N-terminal end of the polypeptide
Aminopeptidases
240
It sequentially cleaves peptide bonds beginning at the C-terminal end of the polypeptide
Carboxypeptidases
241
Enzymes that cleave internal peptide bonds
Endopeptidases
242
Enzymes under Endopeptidases
1. Trypsin
2. Chymotrypsin
3. Elastase
4. Pepsin
5. Thermolysin
243
It cleaves peptide bonds at the carboxyl end of the two strongly basic amino acids: arginine and lysine
Trypsin
244
It cleaves peptide bonds at the carboxyl end of the three aromatic amino acids: phenylalanine, tyrosine, & trptophan; and Leucine
Chymotrypsin
245
It cleaves on the carboxyl side of Gly and Ala
Elastase
246
It cleaves peptide bonds at the amino end of the three aromatic amino acids: phenylalanine, tyrosine, tryptophan; acidic amino acids, Asp and Glu; and Ile
Pepsin
247
It cleaves peptide bonds at the amino end of the three aromatic amino acids, Phe, Tyr, Trp; and amino acids with bulky nonpolar R groups, Leu, Ile, and Val
Thermolysin
248
Other methods for determining the N-terminal end (chemical method)
1. Sanger's Method
2. Edman Degradation
249
The key reagent in this method for identifying the N-terminus is 1-fluoro-2,4-dinitrobenzene
Sanger's Method
250
- can be done sequentially one residue at a time on the same sample
- usually, one can determine the first 20 or so amino acids from the N-terminus by this method
Edman Degradation
251
What is the key reagent in the
Edman degradation?
phenyl isothiocyanate
252
Other methods for determining the C-terminal end (chemical method)
Hydrazine Method
253
Hydrazine reacts with all amino acids whose carboxyl group is bound in peptide linkage, creating ____ ____ ____
Amino acyl hydrazides
254
It regulates body growth
Growth hormones
