Abstract: The present application relates, in general, to compositions or variants of anti-TSLP antibody tezepelumab having increased stability compared to tezepelumab when stored over long periods of time.

Abstract: Provided herein are methods of processing a polypeptide or protein for analysis, e.g., peptide mapping analysis by mass spectrometry. In exemplary embodiments, the method comprises incubating a digested sample at a mildly acidic pH and/or in the presence of a chaotrope, wherein the digested sample is produced by digesting a polypeptide with a protease to produce a digested sample comprising at least two peptides. In exemplary embodiments, the method comprises digesting the polypeptide with a protease which cleaves C-terminal to tryptophan to produce a digested sample comprising at least two peptides. In exemplary embodiments, the method comprises digesting the polypeptide with trypsin at an enzyme:substrate (E:S) weight ratio of about 1:1 to about 1:15 to produce a digested sample comprising at least two peptides. In exemplary aspects, the digested sample comprises at least one or two peptides each comprising a tyrosine at the C-terminus.

Abstract: Provided herein are methods of identifying structures, e.g., attributes, of a therapeutic protein or a target that affect an interaction between the therapeutic protein and the target. In exemplary embodiments, the method comprises: (a) applying a stress to a first sample comprising therapeutic proteins or targets; (b) contacting the first sample with a second sample comprising targets or therapeutic proteins to form a mixture comprising (i) therapeutic protein-target complexes, (ii) unbound therapeutic proteins, and (iii) unbound targets; and (c) separating the mixture into at least two fractions, wherein an unbound fraction comprises unbound therapeutic proteins or unbound targets and a bound fraction comprises therapeutic protein-target complexes; and (d) for each of the unbound fraction and bound fraction, identifying and quantifying the abundance of the structures, e.g., attribute, present on a species of the therapeutic protein or target.