In molecular biology, alpha-amylase inhibitor (or α-...) is a protein family which inhibits

mammalia Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur o ...

alpha-amylase α-Amylase is an enzyme (EC 3.2.1.1; systematic name 4-α-D-glucan glucanohydrolase) that hydrolyses α bonds of large, α-linked polysaccharides, such as starch and glycogen, yielding shorter chains thereof, dextrins, and maltose: :Endohyd ...

s specifically, by forming a tight stoichiometric 1:1

complex Complex commonly refers to: * Complexity, the behaviour of a system whose components interact in multiple ways so possible interactions are difficult to describe ** Complex system, a system composed of many components which may interact with each ...

with alpha-amylase. This family of inhibitors has no action on

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

and

microbial A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...

alpha amylases. A

crystal structure In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions or molecules in a crystal, crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric pat ...

has been determined for tendamistat, the 74-amino acid inhibitor produced by '' Streptomyces tendae'' that targets a wide range of

mammalian Mammals () are a group of vertebrate animals constituting the class (biology), class Mammalia (), characterized by the presence of mammary glands which in Female#Mammalian female, females produce milk for feeding (nursing) their young, a ...

alpha-amylases. The binding of tendamistat to alpha-amylase leads to the

steric Steric effects arise from the spatial arrangement of atoms. When atoms come close together there is a rise in the energy of the molecule. Steric effects are nonbonding interactions that influence the shape ( conformation) and reactivity of ions ...

blockage of the

active site In biology and biochemistry, the active site is the region of an enzyme where substrate molecules bind and undergo a chemical reaction. The active site consists of amino acid residues that form temporary bonds with the substrate (binding site) a ...

of the

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

. The crystal

structure A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...

of tendamistat revealed an immunoglobulin-like fold that could potentially adopt multiple conformations. Such molecular flexibility could enable an induced-fit type of binding that would both optimise binding and allow broad target specificity.

References

{{InterPro content, IPR000833 Protein domains