Related Experiment Video
Updated: Jul 19, 2026

Enzymatic Modification and Flow Cytometry Assessment of Yeast Surface Displayed Proteins
Published on: May 30, 2025
Change in substrate preference of Streptomyces aminopeptidase through modification of the environment around the
Jiro Arima1, Yoshiko Uesugi, Masaki Iwabuchi
1Research Institute for Biological Sciences (RIBS), Okayama, 7549-1 Kibichuo-cho, Kaga-gun, Okayama 716-1241, Japan.
Abstract:
We attempted to alter the substrate preference of aminopeptidase from Streptomyces septatus TH-2 (SSAP). Because Asp198 and Phe221 of SSAP are located in the substrate binding site, we screened 2,000 mutant enzymes with D198X/F221X mutations. By carrying out this examination, we obtained two enzymes; one specifically hydrolyzed an arginyl derivative, and the other specifically hydrolyzed a cystinyl derivative (65- and 12.5-fold higher k(cat) values for hydrolysis of p-nitroanilide derivatives than those of the wild type, respectively).
More Related Videos
09:47The Determination of Protease Specificity in Mouse Tissue Extracts by MALDI-TOF Mass Spectrometry: Manipulating PH to Cause Specificity Changes
Published on: May 25, 2018
06:50Computational Prediction of Amino Acid Preferences of Potentially Multispecific Peptide-Binding Domains Involved in Protein-Protein Interactions
Published on: January 26, 2024
Related Concept Videos
Introduction to Mechanisms of Enzyme Catalysis
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Induced-fit Model
Enzymes exhibit substrate specificity, meaning that they can only bind to certain substrates. This is mainly determined by the shape and chemical characteristics of...
Ligand Binding and Linkage
Enzymes
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Ligand Binding Sites
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...