Isolation, fractionation, and some chemical studies on Kleinhovia hospita Linn. seed protein

Figures & data

Table 1. Nitrogen solubility of K. hospita seed protein in aqueous solution at different pHs.

pH of the aqueous solution	Soluble protein* (%)
2	56.15 ± 0.11
3	54.49 ± 0.05
4	48.67 ± 0.14
5	50.14 ± 0.18
6	51.21 ± 0.09
7	57.31 ± 0.29
8	64.26 ± 0.13
9	66.33 ± 0.08
10	68.87 ± 0.21
11	78.04 ± 0.10
12	92.96 ± 0.27

*Values are mean ± SD, n = 3.

Table 2. Nitrogen solubility of K. hospita seed protein in different salt concentration at pH 7.0.

	Soluble protein* (%)
Molar concentration of different salts	NaCl	KCl	MgCl2, 6H2O	MgSO4, 7H2O
0.1	39.95 ± 0.12	44.29 ± 0.06	59.04 ± 0.09	72.54 ± 0.04
0.2	41.22 ± 0.06	43.52 ± 0.04	60.22 ± 0.12	73.13 ± 0.09
0.3	41.64 ± 0.07	45.84 ± 0.18	60.45 ± 0.13	75.19 ± 0.05
0.4	43.35 ± 0.04	47.17 ± 0.05	62.16 ± 0.12	77.68 ± 0.17
0.5	45.07 ± 0.08	50.92 ± 0.03	69.82 ± 0.08	78.22 ± 0.06
0.6	47.11 ± 0.08	54.93 ± 0.21	71.12 ± 0.24	79.89 ± 0.09
0.7	48.36 ± 0.15	49.06 ± 0.07	63.47 ± 0.03	78.17 ± 0.12
0.8	48.01 ± 0.09	46.08 ± 0.11	61.56 ± 0.07	76.35 ± 0.10
0.9	50.22 ± 0.05	47.74 ± 0.07	58.98 ± 0.14	76.02 ± 0.04
1.0	51.46 ± 0.17	44.02 ± 0.05	58.47 ± 0.11	75.54 ± 0.09

*Values are mean ± SD, n = 3.

Table 3. Proximate chemical analysis of the K. hospita seed and de-oiled seed.

Parameter	Seed*	De-oiled seed*
Moisture (%)	18.21 ± 0.71	13.10 ± 0.45
Ash (%)	6.32 ± 0.12	5.95 ± 0.24
Nitrogen (%)	1.92 ± 0.07	2.36 ± 0.11
Protein (%)	12.00 ± 0.31	14.75 ± 0.49

*Values are mean ± SD, n = 3

Table 4. Amino acid composition of K. hospita seed protein.

Name of amino acids	TPI (g/16 g N)	Albumin (g/16 g N)	Globulin (g/16 g N)	Prolamin (g/16 g N)	Glutelin (g/16 g N)	Soybean protein^c (g/16 g N)
Aspartic acid + asparagine	7.13	9.16	6.24	10.27	3.11	11.60
Glutamic acid + glutamine	25.69	24.27	16.05	13.54	12.67	19.10
Serine	5.27	5.54	5.11	8.95	16.43	5.60
Histidine^a	3.08	4.74	2.12	0.29	6.65	2.80
Glycine	8.22	8.02	15.06	11.08	20.17	4.20
Threonine^a	4.92	4.19	3.68	16.45	8.52	4.10
Arginine^a	6.94	5.67	4.07	1.35	6.34	7.70
Alanine	6.41	6.12	5.62	3.68	7.28	4.30
Tyrosine	6.77	7.18	10.19	8.87	1.97	3.80
Methionine^a	0.60	1.29	2.03	5.14	1.41	1.40
Valine^a	3.26	4.07	5.54	4.22	2.74	5.00
Phenylalanine^a	5.97	4.56	4.61	3.15	1.06	5.20
Isoleucine^a	2.75	2.21	7.17	3.43	1.14	4.60
Leucine^a	4.86	4.95	7.33	3.18	1.58	7.80
Lysine^a	8.12	8.03	5.18	6.40	8.93	6.40
Cysteine	–	–	–	–	–	1.80
E/T (%)^b	40.50	39.71	41.73	43.61	38.37	46.83

^aEssential amino acids.

^bRatio of total essential amino acids to total amino acids.

^cBrul’e and Savoie (1998).

Table 5. Molecular weights of K. hospita seed proteins, as determined by a gel filtration procedure.

Proteins	Elution volume/void volume (V/V0)	Molecular weight determined from the standard curve (Daltons)^a	Molecular weight determined by Whitaker’s equation (Daltons)	Literature molecular weight (Daltons)^b
BSA^c	1.38	–	66,069	66,430
Ovalbumin	1.56	–	44,668	45,000
Pepsin	1.67	–	34,673	34,700
Lysozyme	2.07	–	14,125	14,300
Kleinhovia hospita seed proteins
Component A	1.09	125,893	126,599	–
Component B	1.69	31,989	33,009	–
Component C	1.95	18,197	18,435	–

^aWhitaker^[23,24].

^bLiterature of molecular weights of standard proteins from Sigma Chemical Co., St. Louis, MO.

^cBovine serum albumin.

Figure 1. Gel filtration chromatography of K. hospita seed protein in Sephadex G-100.

Figure 2. SDS–PAGE of K. hospita seed protein (TPI: total protein isolate; F1: albumin; F2: globulin; F3: prolamin; F4: glutelin; and M: marker).

Figure 3. Scanning electron micrographs of K. hospita seed protein isolate (TPI) and four fractions (albumin, globulin, prolamin, and glutelin).

Brul’e, D.; Savoie, L. In Vitro Digestibility of Protein and Amino Acids in Protein Mixture. Journal of the Science of Food and Agriculture 1998, 43, 361–372. DOI: 10.1002/jsfa.2740430409.

 Web of Science ®Google Scholar

Whitaker, J. R.; Determination of Molecular Weights of Proteins by Gel Filtration on Sephadex. Analytical Chemistry 1963, 35, 1950–1953. DOI: 10.1021/ac60205a048.

 Web of Science ®Google Scholar

Whitaker, J. R.; Correction. Determination of Molecular Weights of Proteins by Gel Filtration on Sephadex. Analytical Chemistry 1964, 36, 89. DOI: 10.1021/ac60207a072.

 Web of Science ®Google Scholar