文档介绍：Section B Amino acid and protein
General introduction
Amino acid structure (B1)
Acid and bases (B2)
Protein structure (B3)
Myoglobin and Hemoglobin (B4)
Collagen (B5)
Protein purification (B6, B7,B8)
Protein sequencing (B9)
Proteins are polymers(多聚体) of amino acids.
-20 amino acids (氨基酸) millions of proteins with different properties and activities.
Protein structures are studied at primary, secondary, tertiary and quaternary levels.
B0. General Introduction
Proteins have widely diverse forms and functions.
enzymes(酶), hormones(激素,荷尔蒙), antibodies(抗体), transporters(转运蛋白),
muscle(肌肉), lens protein of eyes(眼睛晶状体), spider webs(蜘蛛网), rhinoceros horn(犀牛角), antibiotics(抗生素),
mushroom poisons(蘑菇毒素).
Fireflies emit light catalyzed by luciferase(荧光素酶) with ATP
A few examples on protein diversity…
Erythrocytes(红细胞) contain a large amount of
hemoglobins(血红蛋白), the oxygen-transporting protein.
The protein keratin (角蛋白) is the chief ponents of hair, horn, wool, nails and feathers.
Section B1 Amino acid structure
1. All natural proteins were found to be built from the same set of 20 standard -amino acids.
2. The 20 amino acids are usually grouped according to the properties (mainly polarity) of their R groups.
3. Nonstandard amino acids are found in certain proteins, generally as a result of post-translational modifications.
4. The amino acids ionize in aqueous solutions.
1. All natural proteins were found to be built from the same set of 20 standard -amino acids
The earliest studies of proteins focused on the free amino acids derived from these proteins.
The 1st amino acid (asparagine) was discovered in 1806 from asparagus (a green vegetable).
The last (threonine) was not identified until 1938!
Glutamate from wheat gluten (sticky). Tyrosine from cheese .