The protonation state and activity of enzymes in low-water media are affected by the aqueous pH before drying ("pH memory"). However, both protonation and activity will change if buffer ions can be removed as volatile or organic-extractable weak acids or bases. With NH4OOCH buffers, in which both ions can be removed, pH memory disappears completely for subtilisin-catalyzed transesterification i...

Chemical modification of the amino groups of plasminostreptin with 2,4,6-trinitrobenzene sulfonic acid or O-methylisourea completely abolished its inhibitory activities against trypsin (EC 3.4.21.4) and plasmin (EC 3.4.21.7). This indicated that plasminostreptin requires at least 1 lysine residue for its trypsin and plasmin inhibitory activities. Incubation of plasminostreptin with a small amou...

The structure of native subtilisin has been partially refined at 2.0 A to an R index of 0.23 (unconstrained). During refinement it became clear that the originally assigned side chain dihedral angle, x1 = 98”, for the catalytic Ser-221 was incorrect. A new value for x, = -100” was deduced by inspection of a “partial structure” difference-Fourier map, and the new location for Oy of Ser-221 is no...

We report on selected research presented at the ACC 66th Annual Scientific Session and Expo, including sessions on proprotein convertase subtilisin/kexin type 9 inhibitors, anti-Xa anticoagulants, and a direct thrombin inhibitor.

Many socially important fungi encode an elevated number of subtilisin-like serine proteases, which have been shown to be involved in fungal mutualisms with grasses and in parasitism of insects, nematodes, plants, other fungi, and mammalian skin. These proteins have endopeptidase activities and constitute a significant part of fungal secretomes. Here, we use comparative genomics to investigate t...