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Peptides and Proteins:- Some Proteins Contain Chemical Groups Other Than Amino Acids

المؤلف:  David L. Nelson، Michael M. Cox

المصدر:  Lehninger Principles of Biochemistry

الجزء والصفحة:  88

2026-04-14

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Peptides and Proteins: -Some Proteins Contain Chemical Groups Other Than Amino Acids

Many proteins, for example the enzymes ribonuclease A and chymotrypsinogen, contain only amino acid residues and no other chemical constituents; these are considered simple proteins. However, some proteins contain permanently associated chemical components in addition to amino acids; these are called conjugated proteins. The non–amino acid part of a conjugated protein is usually called its prosthetic group. Conjugated proteins are classified on the basis of the chemical nature of their prosthetic groups (Table 3–4); for example, lipoproteins contain lipids, glycoproteins contain sugar groups, and metalloproteins contain a specific metal. A number of proteins contain more than one pros thetic group. Usually, the prosthetic group plays an important role in the protein’s biological function.