Amino Acids/analysis; Immunoglobulin G; Macroglobulins; Peptides; gamma-Globulins; Alkylation; Amino Acid Sequence; Animals; Carboxypeptidases; Chemical Phenomena; Chemistry; Chromatography, Gel; Chromatography, Thin Layer; Diphtheria Antitoxin; Electrophoresis; Endopeptidases; Horses; Humans; Hydrogen-Ion Concentration; Immunoglobulin G/analysis; Macroglobulins/analysis; Multiple Myeloma/blood; Peptide Hydrolases; Peptides/analysis; Peptides/isolation & purification; Species Specificity; Sulfonic Acids; Waldenstrom Macroglobulinemia/blood; gamma-Globulins/analysis