κ-Casein from milk

Typical Properties
CAS	9000-71-9
Catalog	ACM9000719-17
Molecular Weight	2061.96 g/mol
Melting Point	280 °C (dec.) (lit.)
Purity	≥70 %
Density	1.26 g/cm3
Solubility	H2O: insoluble, forms a cloudy suspension
Appearance	Powder
Storage	−20 °C
Biological Source	Bovine Milk
Color	white to off-white
Composition	≥70% (PAGE)
EC Number	232-555-1
Feature	·Excellent water resistance ·Excellent fluidity ·Good machinability ·Strong dispersion ·Good biocompatibility
Grade	Reagent Grade
MDL Number	MFCD00081481
Quality Level	200
Shipping	Ambient
Solvent	Water
Stability	Stable. Combustible. Incompatible with strong oxidizing agents.

Overview

Description

κ-Casein is the smallest and occurs in two main variants, A and B. κ-Caseins surround αs-casein and β-caseins in the micelles. κ-Caseins have no phosphoseryl clusters, but have tetrasaccharide chains attached to threonyl residues 31, 33, 35, and 36 (variant A only). Its N-terminal is hydrophobic, while the other terminal is polar and has no Asp or Glu residues. At pH 6.6, the residues of the C-terminal plus the carbohydrate chains confer a net negative charge of − 16 or − 17. The disulfide form exists in vivo as there is sulfhydryl oxidase activity in raw milk. This molecule is thus highly amphoteric and plays a crucial role in the coagulation of milk catalyzed by chymosin.

Features

·Excellent water resistance
·Excellent fluidity
·Good machinability
·Strong dispersion
·Good biocompatibility

Application

·Quantitative analysis of casein concentration as a standard to evaluate the ability of strains to hydrolyze casein in HM Mozzarella cheese
·Preparation of LPS-deficient cow's milk protein for lymphocyte proliferation assay
·As a reversed-phase high performance liquid chromatography (RP-HPLC) standard for quantitative analysis of kappa-casein concentrations in skim milk samples