Alirocumab and evolocumab are monoclonal antibodies that block proprotein convertase subtilisin/kexin type 9 (PCSK9), a circulating protein that degrades low-density lipoprotein (LDL) receptors. These therapies increase LDL receptors on the cell surface and reduce plasma LDL cholesterol. Both therapies are approved to lower LDL cholesterol, a causative agent for atherosclerotic cardiovascular d...

A guinea pig intratracheal test was used to set occupational operating guidelines for new enzyme proteins used in the detergent industry. In these studies, animals were intratracheally dosed with different levels of enzyme protein and sera from the animals were titered for allergic antibody to the enzyme. The amount of antibody produced to an enzyme was compared to the amount of antibody produc...

An intranasal (i.n.) dosing model was developed in mice as a potential alternative to more difficult, time-consuming, and costly guinea pig intratracheal (GPIT) or mouse intratracheal models for assessment of the respiratory immunogenicity of detergent enzymes. Using a benchmark enzyme, Alcalase (protease subtilisin Carlsberg), studies were conducted to standardize the model in terms of mouse s...

A form of systemic tetanus with atypical symptoms was observed in mice injected in the left thigh with a mixture of tetanus toxin and antibody produced in guinea pigs against a fragment of toxin obtained from a subtilisin digest of the crystallized toxin. The mice did not show typical symptoms of the local tetanus such as convulsions or spastic paralysis of the injected limb.

Arylboronic acids were found to be strong competitive inhibitors of subtilisin and chymotrypsin. The binding constants are strongly pH dependent and give a Hammett-type plot with a slope of -0.885. The pH dependence, the Hammett plot, and nmr model-system studies indicate that inhibition is due to electron-pair donation by the active site histidine to the bound inhibitor.

subtilisins and proteinase K.]) Many protein cngincering studjes on subtilisins6) show that amino acid substitution can change the substrate specificity, pH depencience. thermostability, and eatalytie activity. Subtilisin BPN' mutant N218S (Asn218 is rcplaced by serine) has more thermostability than the wild-type cnzyme;7) Asn218 is threc rcsidues fi'om one of the catalytic residues. Ser221. Th...

A study of the comparative specificities of cr-chymotrypsin and subtilisin Carlsberg has been focused mainly on the extent to which a-acetamido groups of some specific and nonspecific activated ester substrates affect the reactivity of each enzyme. Comparisons are based upon k, and k,: K,,, corrected for substrate intrinsic reactivities ((k,), and (k,: K&J. Among p-nitrophenyl P-phenylpropionat...

Rat liver microsomes contain three spectrally distinguishable forms of cytochrome P-450. Each form is identified qualitatively and quantitatively by visible spectral changes that occur when the cytochromes P-450 combine with various ligands, such as cyanide. In addition to cytochrome P-450, rat liver microsomes also contain cytochrome b6, which may be removed from the microsomes by digestion wi...

A gene encoding a subtilisin-like protease, designated islandisin, from the extremely thermophilic bacterium Fervidobacterium islandicum (DSMZ 5733) was cloned and actively expressed in Escherichia coli. The gene was identified by PCR using degenerated primers based on conserved regions around two of the three catalytic residues (Asp, His, and Ser) of subtilisin-like serine protease-encoding ge...

OBJECTIVE Cyclosporin A (CsA) is an immunosuppressant commonly used to prevent organ rejection but is associated with hyperlipidemia and an increased risk of cardiovascular disease. Although studies suggest that CsA-induced hyperlipidemia is mediated by inhibition of low-density lipoprotein receptor (LDLr)-mediated lipoprotein clearance, the data supporting this are inconclusive. We therefore s...