Polyketides

From LipidomicsWiki

Contents 1 Basics 1.1 Structure 1.2 Natural sources 1.3 Nomenclature 1.4 Biophysical properties 2 Biology / biochemistry 2.1 Biochemical synthesis 2.2 Metabolism 2.3 Enzymes/gene lists 2.4 Associated biological processes 3 Technology 3.1 Analysis methods 3.2 Chemical synthesis

Basics

Polyketides (PK) are synthesized by classic enzymes as well as iterative and multimodular enzymes with semiautonomous active sites that share mechanistic features with the fatty acid synthases, including the involvement of specialized acyl carrier proteins; however, polyketide synthases generate a much greater diversity of natural product structures, many of which have the character of lipids. The class I polyketide synthases form constrained macrocyclic lactones, typically ranging in size from 14 to 40 atoms, whereas class II and III polyketide synthases generate complex aromatic ring systems. PK backbones are often further modified by glycosylation, methylation, hydroxylation, oxidation, and/or other processes. Some PK are linked with nonribosomally synthesized peptides to form hybrid scaffolds.

Many commonly used antimicrobial, antiparasitic, and anticancer agents are polyketides or polyketide derivatives. Important examples of these drugs include erythromycins, tetracylines, nystatins, avermectins, and antitumor epothilones. Other PK are potent toxins. The possibility of recombining and reengineering the enzymatic modules that assemble PK has recently stimulated the search for novel “unnatural” natural products, especially in the antibiotic arena.

Structure

Natural sources

Nomenclature

Biophysical properties

Biology / biochemistry

Biochemical synthesis

Metabolism

Enzymes/gene lists

Associated biological processes

Technology

Analysis methods

Chemical synthesis

PK classes and subclasses

Macrolide polyketides Aromatic polyketides Nonribosomal peptide/polyketide hybrids Other