membrane protein of the tetraspanin family also referred to as melanoma 1 antigen ocular melanoma associated antigen melanoma associated antigen me491 lysosome associated membrane glycoprotein 3 granulophysin melanoma associated antigen mla1 u201c chimeric u201d antibodies are immunoglobulins in which a portion of the heavy and or light chain is identical with or homologous to corresponding sequences in antibodies derived from a particular species or belonging to a particular antibody class or subclass while the remainder of the chain s is identical with or homologous to corresponding sequences in antibodies derived from another species or belonging to another antibody class or subclass as well as fragments of such antibodies so long as they exhibit the desired biological activity u s pat no 4 816 567 and morrison et al proc natl acad sci usa 81 6851 6855 1984 u201c humanized u201d forms of non human e g murine antibodies are specific chimeric immunoglobulins immunoglobulin chains or fragments thereof such as fv fab fab u2032 f ab 2 or other antigen binding subsequences of antibodies which contain minimal sequence derived from non human immunoglobulin for the most part humanized antibodies are human immunoglobulins recipient antibody in which residues from the complementarity determining regions cdrs of the recipient antibody are replaced by residues from the cdrs of a non human species donor antibody such as mouse rat or rabbit having the desired specificity affinity and capacity in some instances fv framework region fr residues of the human immunoglobulin are replaced by corresponding non human fr residues furthermore the.