Abstract: Heterodimeric Fc variants comprising one or more asymmetric amino acid mutations in the CH2 domain and having increased selectivity of binding to Fc?RIIb as compared to a parental Fc region, polypeptides comprising the heterodimeric Fc variants and polynucleotides encoding the heterodimeric Fc variants. The one or more asymmetric mutations comprise replacement of a loop in the CH2 domain, a mutation at position 236 in the CH2 domain, or a combination of replacement of a loop in the CH2 domain and a mutation at position 236 in the CH2 domain.

Abstract: Fc variants are described comprising one or more amino acid mutations that increase the stability of the Fc variant as compared to a parental Fc that does not include the one or more amino acid mutations, as well as polypeptides comprising an Fc variant and polynucleotides encoding an Fc variant.

Abstract: Systems and methods for variable fitting include communicating one or more descriptions for a system exhibiting a variable value. In response, a response consisting of a first or second indication is received from the user of the disclosed systems and methods. The first and second indications being that the one or more descriptions are respectively considered to be in a first or second class with respect to the variable. The variable value is changed based on the received response. This communicating, receiving, and changing is repeated until an exit condition is considered to exist.

Abstract: Provided is a method of quantitatively determining the ability of individual IgG heavy chains to selectively pair with a particular IgG light chain when the heavy chains and two unique light chains are co-expressed. The method provides results with reasonable throughput and is robust and accurate. The co-expressed heavy and light chains do not need to be isolated and purified which enables more efficient screening.

Abstract: Systems and methods for physical parameter fitting include communicating one or more three-dimensional structures for a molecular system exhibiting a physical parameter value. In response, a dichotomous classification consisting of a first or second indication is received from the user of the disclosed systems and methods. The first and second indications being that the one or more three-dimensional structures are respectively deemed to be in a first or second dichotomous structural class with respect to the physical parameter. The physical parameter value is altered based on the received dichotomous classification. This communicating, receiving, and altering is repeated until an exit condition is deemed to exist.

Abstract: Provided is a method of quantitatively determining the ability of individual IgG heavy chains to selectively pair with a particular IgG light chain when the heavy chains and two unique light chains are co-expressed. The method provides results with reasonable throughput and is robust and accurate. The co-expressed heavy and light chains do not need to be isolated and purified which enables more efficient screening.