The variations in the physical characteristics between different proteins are influenced by the overall amino acid compositions, but even more important is the unique amino acid

Sequence

Explanation:

Physical properties of the proteins are foundation of biological function of them.

A protein molecule is made up from the long chain of the amino acids. Each amino acid is linked to its neighbor by covalent peptide bond. Thus, proteins are also called as polypeptides.

Each protein has unique sequence of the amino acids, exactly same from one molecule to next. Different proteins has its own particular sequence of amino acid. This sequence is responsible for folding and binding of the protein and also its physical characteristics.