Oligomeric status of human cystathionine beta-synthase modulates AdoMet binding Angel L. Pey Luis Alfonso Martínez-Cruz Jan P. Kraus Tomas Majtan 10.25376/hra.7801052.v1 https://hra.figshare.com/articles/journal_contribution/Oligomeric_status_of_human_cystathionine_beta-synthase_modulates_AdoMet_binding/7801052 <div>Cystathionine beta-synthase (CBS) plays a key role in the metabolism of sulfur-containing amino acids. CBS is a multidomain tetrameric enzyme allosterically activated by S-adenosylmethionine (AdoMet). Recent crystallographic analyses of engineered CBS lacking the loop made up of residues 516–525 revealed discrepancies in AdoMet binding compared to previous biophysical studies on a full-length CBS. Here, we show that removal of the loop 516–525 functionally eliminates the high affinity sites responsible for kinetic stabilization of the full-length enzyme and yields a dimeric AdoMet-inducible enzyme, in which kinetic stabilization is now exerted by AdoMet binding to the remaining low affinity sites.</div> 2019-03-05 01:30:11 Calorimetry Study S-Adenosylmethionine (SAM) cystathionine beta synthase oligomerization status Enzymes Molecular Biology Biochemistry and Cell Biology not elsewhere classified